diff --git a/.appveyor.yml b/.appveyor.yml
index a0d3292f1..ccc70ab7c 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -4,9 +4,8 @@ init:
   - git config --global core.autocrlf input
 
 install:
-  - cinst jdk8 -params 'installdir=C:\\jdk8'
-  - SET JAVA_HOME=C:\jdk8
-  - SET PATH=C:\jdk8\bin;%PATH%
+  - SET JAVA_HOME=C:\Program Files\Java\jdk1.8.0
+  - SET PATH=%JAVA_HOME%\bin;%PATH%
 
   - ps: |
       Add-Type -AssemblyName System.IO.Compression.FileSystem
@@ -20,4 +19,8 @@ install:
   - SET PATH=C:\sbt\sbt\bin;%PATH%
   - SET SBT_OPTS=-XX:MaxPermSize=2g -Xmx4g -Dfile.encoding=UTF8
 test_script:
-  - sbt "scripted actions/* server/*"
+  - sbt "scripted actions/*" "testOnly sbt.ServerSpec"
+
+cache:
+  - '%USERPROFILE%\.ivy2\cache'
+  - '%USERPROFILE%\.sbt'
diff --git a/.travis.yml b/.travis.yml
index a8a539237..c6e2d000e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -28,7 +28,7 @@ env:
     - SBT_CMD="scripted dependency-management/*4of4"
     - SBT_CMD="scripted java/* package/* reporter/* run/* project-load/*"
     - SBT_CMD="scripted project/*1of2"
-    - SBT_CMD="scripted project/*2of2 server/*"
+    - SBT_CMD="scripted project/*2of2"
     - SBT_CMD="scripted source-dependencies/*1of3"
     - SBT_CMD="scripted source-dependencies/*2of3"
     - SBT_CMD="scripted source-dependencies/*3of3"
diff --git a/build.sbt b/build.sbt
index d832e23f4..3cf04650b 100644
--- a/build.sbt
+++ b/build.sbt
@@ -318,12 +318,13 @@ lazy val actionsProj = (project in file("main-actions"))
 
 lazy val protocolProj = (project in file("protocol"))
   .enablePlugins(ContrabandPlugin, JsonCodecPlugin)
+  .dependsOn(collectionProj)
   .settings(
     testedBaseSettings,
     scalacOptions -= "-Ywarn-unused",
     scalacOptions += "-Xlint:-unused",
     name := "Protocol",
-    libraryDependencies ++= Seq(sjsonNewScalaJson.value),
+    libraryDependencies ++= Seq(sjsonNewScalaJson.value, ipcSocket),
     managedSourceDirectories in Compile +=
       baseDirectory.value / "src" / "main" / "contraband-scala",
     sourceManaged in (Compile, generateContrabands) := baseDirectory.value / "src" / "main" / "contraband-scala",
@@ -355,6 +356,9 @@ lazy val commandProj = (project in file("main-command"))
       exclude[ReversedMissingMethodProblem]("sbt.internal.CommandChannel.*"),
       // Added an overload to reboot. The overload is private[sbt].
       exclude[ReversedMissingMethodProblem]("sbt.StateOps.reboot"),
+      // Replace nailgun socket stuff
+      exclude[MissingClassProblem]("sbt.internal.NG*"),
+      exclude[MissingClassProblem]("sbt.internal.ReferenceCountedFileDescriptor"),
     ),
     unmanagedSources in (Compile, headerCreate) := {
       val old = (unmanagedSources in (Compile, headerCreate)).value
@@ -463,7 +467,7 @@ lazy val mainProj = (project in file("main"))
 lazy val sbtProj = (project in file("sbt"))
   .dependsOn(mainProj, scriptedSbtProj % "test->test")
   .settings(
-    baseSettings,
+    testedBaseSettings,
     name := "sbt",
     normalizedName := "sbt",
     crossScalaVersions := Seq(baseScalaVersion),
@@ -477,6 +481,7 @@ lazy val sbtProj = (project in file("sbt"))
     buildInfoKeys in Test := Seq[BuildInfoKey](fullClasspath in Compile),
     connectInput in run in Test := true,
     outputStrategy in run in Test := Some(StdoutOutput),
+    fork in Test := true,
   )
   .configure(addSbtCompilerBridge)
 
diff --git a/main-command/src/main/java/sbt/internal/NGUnixDomainServerSocket.java b/main-command/src/main/java/sbt/internal/NGUnixDomainServerSocket.java
deleted file mode 100644
index 89d3bcf43..000000000
--- a/main-command/src/main/java/sbt/internal/NGUnixDomainServerSocket.java
+++ /dev/null
@@ -1,178 +0,0 @@
-// Copied from https://github.com/facebook/nailgun/blob/af623fddedfdca010df46302a0711ce0e2cc1ba6/nailgun-server/src/main/java/com/martiansoftware/nailgun/NGUnixDomainServerSocket.java
-
-/*
-
- Copyright 2004-2015, Martian Software, Inc.
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
-
- */
-package sbt.internal;
-
-import java.io.IOException;
-import java.net.ServerSocket;
-import java.net.Socket;
-import java.net.SocketAddress;
-import java.util.concurrent.atomic.AtomicInteger;
-
-import com.sun.jna.LastErrorException;
-import com.sun.jna.ptr.IntByReference;
-
-/**
- * Implements a {@link ServerSocket} which binds to a local Unix domain socket
- * and returns instances of {@link NGUnixDomainSocket} from
- * {@link #accept()}.
- */
-public class NGUnixDomainServerSocket extends ServerSocket {
-  private static final int DEFAULT_BACKLOG = 50;
-
-  // We use an AtomicInteger to prevent a race in this situation which
-  // could happen if fd were just an int:
-  //
-  // Thread 1 -> NGUnixDomainServerSocket.accept()
-  //          -> lock this
-  //          -> check isBound and isClosed
-  //          -> unlock this
-  //          -> descheduled while still in method
-  // Thread 2 -> NGUnixDomainServerSocket.close()
-  //          -> lock this
-  //          -> check isClosed
-  //          -> NGUnixDomainSocketLibrary.close(fd)
-  //          -> now fd is invalid
-  //          -> unlock this
-  // Thread 1 -> re-scheduled while still in method
-  //          -> NGUnixDomainSocketLibrary.accept(fd, which is invalid and maybe re-used)
-  //
-  // By using an AtomicInteger, we'll set this to -1 after it's closed, which
-  // will cause the accept() call above to cleanly fail instead of possibly
-  // being called on an unrelated fd (which may or may not fail).
-  private final AtomicInteger fd;
-
-  private final int backlog;
-  private boolean isBound;
-  private boolean isClosed;
-
-  public static class NGUnixDomainServerSocketAddress extends SocketAddress {
-    private final String path;
-
-    public NGUnixDomainServerSocketAddress(String path) {
-      this.path = path;
-    }
-
-    public String getPath() {
-      return path;
-    }
-  }
-
-  /**
-   * Constructs an unbound Unix domain server socket.
-   */
-  public NGUnixDomainServerSocket() throws IOException {
-    this(DEFAULT_BACKLOG, null);
-  }
-
-  /**
-   * Constructs an unbound Unix domain server socket with the specified listen backlog.
-   */
-  public NGUnixDomainServerSocket(int backlog) throws IOException {
-    this(backlog, null);
-  }
-
-  /**
-   * Constructs and binds a Unix domain server socket to the specified path.
-   */
-  public NGUnixDomainServerSocket(String path) throws IOException {
-    this(DEFAULT_BACKLOG, path);
-  }
-
-  /**
-   * Constructs and binds a Unix domain server socket to the specified path
-   * with the specified listen backlog.
-   */
-  public NGUnixDomainServerSocket(int backlog, String path) throws IOException {
-    try {
-      fd = new AtomicInteger(
-          NGUnixDomainSocketLibrary.socket(
-              NGUnixDomainSocketLibrary.PF_LOCAL,
-              NGUnixDomainSocketLibrary.SOCK_STREAM,
-              0));
-      this.backlog = backlog;
-      if (path != null) {
-        bind(new NGUnixDomainServerSocketAddress(path));
-      }
-    } catch (LastErrorException e) {
-      throw new IOException(e);
-    }
-  }
-
-  public synchronized void bind(SocketAddress endpoint) throws IOException {
-    if (!(endpoint instanceof NGUnixDomainServerSocketAddress)) {
-      throw new IllegalArgumentException(
-          "endpoint must be an instance of NGUnixDomainServerSocketAddress");
-    }
-    if (isBound) {
-      throw new IllegalStateException("Socket is already bound");
-    }
-    if (isClosed) {
-      throw new IllegalStateException("Socket is already closed");
-    }
-    NGUnixDomainServerSocketAddress unEndpoint = (NGUnixDomainServerSocketAddress) endpoint;
-    NGUnixDomainSocketLibrary.SockaddrUn address =
-        new NGUnixDomainSocketLibrary.SockaddrUn(unEndpoint.getPath());
-    try {
-      int socketFd = fd.get();
-      NGUnixDomainSocketLibrary.bind(socketFd, address, address.size());
-      NGUnixDomainSocketLibrary.listen(socketFd, backlog);
-      isBound = true;
-    } catch (LastErrorException e) {
-      throw new IOException(e);
-    }
-  }
-
-  public Socket accept() throws IOException {
-    // We explicitly do not make this method synchronized, since the
-    // call to NGUnixDomainSocketLibrary.accept() will block
-    // indefinitely, causing another thread's call to close() to deadlock.
-    synchronized (this) {
-      if (!isBound) {
-        throw new IllegalStateException("Socket is not bound");
-      }
-      if (isClosed) {
-        throw new IllegalStateException("Socket is already closed");
-      }
-    }
-    try {
-      NGUnixDomainSocketLibrary.SockaddrUn sockaddrUn =
-          new NGUnixDomainSocketLibrary.SockaddrUn();
-      IntByReference addressLen = new IntByReference();
-      addressLen.setValue(sockaddrUn.size());
-      int clientFd = NGUnixDomainSocketLibrary.accept(fd.get(), sockaddrUn, addressLen);
-      return new NGUnixDomainSocket(clientFd);
-    } catch (LastErrorException e) {
-      throw new IOException(e);
-    }
-  }
-
-  public synchronized void close() throws IOException {
-    if (isClosed) {
-      throw new IllegalStateException("Socket is already closed");
-    }
-    try {
-      // Ensure any pending call to accept() fails.
-      NGUnixDomainSocketLibrary.close(fd.getAndSet(-1));
-      isClosed = true;
-    } catch (LastErrorException e) {
-      throw new IOException(e);
-    }
-  }
-}
diff --git a/main-command/src/main/java/sbt/internal/NGUnixDomainSocket.java b/main-command/src/main/java/sbt/internal/NGUnixDomainSocket.java
deleted file mode 100644
index b70bef611..000000000
--- a/main-command/src/main/java/sbt/internal/NGUnixDomainSocket.java
+++ /dev/null
@@ -1,192 +0,0 @@
-// Copied from https://github.com/facebook/nailgun/blob/af623fddedfdca010df46302a0711ce0e2cc1ba6/nailgun-server/src/main/java/com/martiansoftware/nailgun/NGUnixDomainSocket.java
-
-/*
-
- Copyright 2004-2015, Martian Software, Inc.
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
-
- */
-package sbt.internal;
-
-import com.sun.jna.LastErrorException;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-
-import java.nio.ByteBuffer;
-
-import java.net.Socket;
-
-import java.util.concurrent.atomic.AtomicInteger;
-
-/**
- * Implements a {@link Socket} backed by a native Unix domain socket.
- *
- * Instances of this class always return {@code null} for
- * {@link Socket#getInetAddress()}, {@link Socket#getLocalAddress()},
- * {@link Socket#getLocalSocketAddress()}, {@link Socket#getRemoteSocketAddress()}.
- */
-public class NGUnixDomainSocket extends Socket {
-  private final ReferenceCountedFileDescriptor fd;
-  private final InputStream is;
-  private final OutputStream os;
-
-  public NGUnixDomainSocket(String path) throws IOException {
-    try {
-      AtomicInteger fd = new AtomicInteger(
-          NGUnixDomainSocketLibrary.socket(
-              NGUnixDomainSocketLibrary.PF_LOCAL,
-              NGUnixDomainSocketLibrary.SOCK_STREAM,
-              0));
-      NGUnixDomainSocketLibrary.SockaddrUn address =
-        new NGUnixDomainSocketLibrary.SockaddrUn(path);
-      int socketFd = fd.get();
-      NGUnixDomainSocketLibrary.connect(socketFd, address, address.size());
-      this.fd = new ReferenceCountedFileDescriptor(socketFd);
-      this.is = new NGUnixDomainSocketInputStream();
-      this.os = new NGUnixDomainSocketOutputStream();
-    } catch (LastErrorException e) {
-      throw new IOException(e);
-    }
-  }
-
-  /**
-   * Creates a Unix domain socket backed by a native file descriptor.
-   */
-  public NGUnixDomainSocket(int fd) {
-    this.fd = new ReferenceCountedFileDescriptor(fd);
-    this.is = new NGUnixDomainSocketInputStream();
-    this.os = new NGUnixDomainSocketOutputStream();
-  }
-
-  public InputStream getInputStream() {
-    return is;
-  }
-
-  public OutputStream getOutputStream() {
-    return os;
-  }
-
-  public void shutdownInput() throws IOException {
-    doShutdown(NGUnixDomainSocketLibrary.SHUT_RD);
-  }
-
-  public void shutdownOutput() throws IOException {
-    doShutdown(NGUnixDomainSocketLibrary.SHUT_WR);
-  }
-
-  private void doShutdown(int how) throws IOException {
-    try {
-      int socketFd = fd.acquire();
-      if (socketFd != -1) {
-        NGUnixDomainSocketLibrary.shutdown(socketFd, how);
-      }
-    } catch (LastErrorException e) {
-      throw new IOException(e);
-    } finally {
-      fd.release();
-    }
-  }
-
-  public void close() throws IOException {
-    super.close();
-    try {
-      // This might not close the FD right away. In case we are about
-      // to read or write on another thread, it will delay the close
-      // until the read or write completes, to prevent the FD from
-      // being re-used for a different purpose and the other thread
-      // reading from a different FD.
-      fd.close();
-    } catch (LastErrorException e) {
-      throw new IOException(e);
-    }
-  }
-
-  private class NGUnixDomainSocketInputStream extends InputStream {
-    public int read() throws IOException {
-      ByteBuffer buf = ByteBuffer.allocate(1);
-      int result;
-      if (doRead(buf) == 0) {
-        result = -1;
-      } else {
-        // Make sure to & with 0xFF to avoid sign extension
-        result = 0xFF & buf.get();
-      }
-      return result;
-    }
-
-    public int read(byte[] b, int off, int len) throws IOException {
-      if (len == 0) {
-        return 0;
-      }
-      ByteBuffer buf = ByteBuffer.wrap(b, off, len);
-      int result = doRead(buf);
-      if (result == 0) {
-        result = -1;
-      }
-      return result;
-    }
-
-    private int doRead(ByteBuffer buf) throws IOException {
-      try {
-        int fdToRead = fd.acquire();
-        if (fdToRead == -1) {
-          return -1;
-        }
-        return NGUnixDomainSocketLibrary.read(fdToRead, buf, buf.remaining());
-      } catch (LastErrorException e) {
-        throw new IOException(e);
-      } finally {
-        fd.release();
-      }
-    }
-  }
-
-  private class NGUnixDomainSocketOutputStream extends OutputStream {
-
-    public void write(int b) throws IOException {
-      ByteBuffer buf = ByteBuffer.allocate(1);
-      buf.put(0, (byte) (0xFF & b));
-      doWrite(buf);
-    }
-
-    public void write(byte[] b, int off, int len) throws IOException {
-      if (len == 0) {
-        return;
-      }
-      ByteBuffer buf = ByteBuffer.wrap(b, off, len);
-      doWrite(buf);
-    }
-
-    private void doWrite(ByteBuffer buf) throws IOException {
-      try {
-        int fdToWrite = fd.acquire();
-        if (fdToWrite == -1) {
-          return;
-        }
-        int ret = NGUnixDomainSocketLibrary.write(fdToWrite, buf, buf.remaining());
-        if (ret != buf.remaining()) {
-          // This shouldn't happen with standard blocking Unix domain sockets.
-          throw new IOException("Could not write " + buf.remaining() + " bytes as requested " +
-                                "(wrote " + ret + " bytes instead)");
-        }
-      } catch (LastErrorException e) {
-        throw new IOException(e);
-      } finally {
-        fd.release();
-      }
-    }
-  }
-}
diff --git a/main-command/src/main/java/sbt/internal/NGUnixDomainSocketLibrary.java b/main-command/src/main/java/sbt/internal/NGUnixDomainSocketLibrary.java
deleted file mode 100644
index 4d781b6b6..000000000
--- a/main-command/src/main/java/sbt/internal/NGUnixDomainSocketLibrary.java
+++ /dev/null
@@ -1,142 +0,0 @@
-// Copied from https://github.com/facebook/nailgun/blob/af623fddedfdca010df46302a0711ce0e2cc1ba6/nailgun-server/src/main/java/com/martiansoftware/nailgun/NGUnixDomainSocketLibrary.java
-
-/*
-
- Copyright 2004-2015, Martian Software, Inc.
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
-
- */
-package sbt.internal;
-
-import com.sun.jna.LastErrorException;
-import com.sun.jna.Native;
-import com.sun.jna.Platform;
-import com.sun.jna.Structure;
-import com.sun.jna.Union;
-import com.sun.jna.ptr.IntByReference;
-
-import java.io.IOException;
-import java.nio.ByteBuffer;
-import java.util.Arrays;
-import java.util.List;
-
-/**
- * Utility class to bridge native Unix domain socket calls to Java using JNA.
- */
-public class NGUnixDomainSocketLibrary {
-  public static final int PF_LOCAL = 1;
-  public static final int AF_LOCAL = 1;
-  public static final int SOCK_STREAM = 1;
-
-  public static final int SHUT_RD = 0;
-  public static final int SHUT_WR = 1;
-
-  // Utility class, do not instantiate.
-  private NGUnixDomainSocketLibrary() { }
-
-  // BSD platforms write a length byte at the start of struct sockaddr_un.
-  private static final boolean HAS_SUN_LEN =
-      Platform.isMac() || Platform.isFreeBSD() || Platform.isNetBSD() ||
-      Platform.isOpenBSD() || Platform.iskFreeBSD();
-
-  /**
-   * Bridges {@code struct sockaddr_un} to and from native code.
-   */
-  public static class SockaddrUn extends Structure implements Structure.ByReference {
-    /**
-     * On BSD platforms, the {@code sun_len} and {@code sun_family} values in
-     * {@code struct sockaddr_un}.
-     */
-    public static class SunLenAndFamily extends Structure {
-      public byte sunLen;
-      public byte sunFamily;
-
-      protected List getFieldOrder() {
-        return Arrays.asList(new String[] { "sunLen", "sunFamily" });
-      }
-    }
-
-    /**
-     * On BSD platforms, {@code sunLenAndFamily} will be present.
-     * On other platforms, only {@code sunFamily} will be present.
-     */
-    public static class SunFamily extends Union {
-      public SunLenAndFamily sunLenAndFamily;
-      public short sunFamily;
-    }
-
-    public SunFamily sunFamily = new SunFamily();
-    public byte[] sunPath = new byte[104];
-
-    /**
-     * Constructs an empty {@code struct sockaddr_un}.
-     */
-    public SockaddrUn() {
-      if (HAS_SUN_LEN) {
-        sunFamily.sunLenAndFamily = new SunLenAndFamily();
-        sunFamily.setType(SunLenAndFamily.class);
-      } else {
-        sunFamily.setType(Short.TYPE);
-      }
-      allocateMemory();
-    }
-
-    /**
-     * Constructs a {@code struct sockaddr_un} with a path whose bytes are encoded
-     * using the default encoding of the platform.
-     */
-    public SockaddrUn(String path) throws IOException {
-      byte[] pathBytes = path.getBytes();
-      if (pathBytes.length > sunPath.length - 1) {
-        throw new IOException("Cannot fit name [" + path + "] in maximum unix domain socket length");
-      }
-      System.arraycopy(pathBytes, 0, sunPath, 0, pathBytes.length);
-      sunPath[pathBytes.length] = (byte) 0;
-      if (HAS_SUN_LEN) {
-        int len = fieldOffset("sunPath") + pathBytes.length;
-        sunFamily.sunLenAndFamily = new SunLenAndFamily();
-        sunFamily.sunLenAndFamily.sunLen = (byte) len;
-        sunFamily.sunLenAndFamily.sunFamily = AF_LOCAL;
-        sunFamily.setType(SunLenAndFamily.class);
-      } else {
-        sunFamily.sunFamily = AF_LOCAL;
-        sunFamily.setType(Short.TYPE);
-      }
-      allocateMemory();
-    }
-
-    protected List getFieldOrder() {
-      return Arrays.asList(new String[] { "sunFamily", "sunPath" });
-    }
-  }
-
-  static {
-    Native.register(Platform.C_LIBRARY_NAME);
-  }
-
-  public static native int socket(int domain, int type, int protocol) throws LastErrorException;
-  public static native int bind(int fd, SockaddrUn address, int addressLen)
-    throws LastErrorException;
-  public static native int listen(int fd, int backlog) throws LastErrorException;
-  public static native int accept(int fd, SockaddrUn address, IntByReference addressLen)
-    throws LastErrorException;
-  public static native int connect(int fd, SockaddrUn address, int addressLen)
-    throws LastErrorException;
-  public static native int read(int fd, ByteBuffer buffer, int count)
-    throws LastErrorException;
-  public static native int write(int fd, ByteBuffer buffer, int count)
-    throws LastErrorException;
-  public static native int close(int fd) throws LastErrorException;
-  public static native int shutdown(int fd, int how) throws LastErrorException;
-}
diff --git a/main-command/src/main/java/sbt/internal/NGWin32NamedPipeLibrary.java b/main-command/src/main/java/sbt/internal/NGWin32NamedPipeLibrary.java
deleted file mode 100644
index dd4d8f15a..000000000
--- a/main-command/src/main/java/sbt/internal/NGWin32NamedPipeLibrary.java
+++ /dev/null
@@ -1,90 +0,0 @@
-// Copied from https://github.com/facebook/nailgun/blob/af623fddedfdca010df46302a0711ce0e2cc1ba6/nailgun-server/src/main/java/com/martiansoftware/nailgun/NGWin32NamedPipeLibrary.java
-
-/*
-
- Copyright 2004-2017, Martian Software, Inc.
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
-
- */
-package sbt.internal;
-
-import java.nio.ByteBuffer;
-
-import com.sun.jna.*;
-import com.sun.jna.platform.win32.WinNT;
-import com.sun.jna.platform.win32.WinNT.*;
-import com.sun.jna.platform.win32.WinBase.*;
-import com.sun.jna.ptr.IntByReference;
-
-import com.sun.jna.win32.W32APIOptions;
-
-public interface NGWin32NamedPipeLibrary extends Library, WinNT {
-    int PIPE_ACCESS_DUPLEX = 3;
-    int PIPE_UNLIMITED_INSTANCES = 255;
-    int FILE_FLAG_FIRST_PIPE_INSTANCE = 524288;
-
-    NGWin32NamedPipeLibrary INSTANCE =
-            (NGWin32NamedPipeLibrary) Native.loadLibrary(
-                    "kernel32",
-                    NGWin32NamedPipeLibrary.class,
-                    W32APIOptions.UNICODE_OPTIONS);
-
-    HANDLE CreateNamedPipe(
-            String lpName,
-            int dwOpenMode,
-            int dwPipeMode,
-            int nMaxInstances,
-            int nOutBufferSize,
-            int nInBufferSize,
-            int nDefaultTimeOut,
-            SECURITY_ATTRIBUTES lpSecurityAttributes);
-    boolean ConnectNamedPipe(
-            HANDLE hNamedPipe,
-            Pointer lpOverlapped);
-    boolean DisconnectNamedPipe(
-            HANDLE hObject);
-    boolean ReadFile(
-            HANDLE hFile,
-            Memory lpBuffer,
-            int nNumberOfBytesToRead,
-            IntByReference lpNumberOfBytesRead,
-            Pointer lpOverlapped);
-    boolean WriteFile(
-            HANDLE hFile,
-            ByteBuffer lpBuffer,
-            int nNumberOfBytesToWrite,
-            IntByReference lpNumberOfBytesWritten,
-            Pointer lpOverlapped);
-    boolean CloseHandle(
-            HANDLE hObject);
-    boolean GetOverlappedResult(
-            HANDLE hFile,
-            Pointer lpOverlapped,
-            IntByReference lpNumberOfBytesTransferred,
-            boolean wait);
-    boolean CancelIoEx(
-            HANDLE hObject,
-            Pointer lpOverlapped);
-    HANDLE CreateEvent(
-            SECURITY_ATTRIBUTES lpEventAttributes,
-            boolean bManualReset,
-            boolean bInitialState,
-            String lpName);
-    int WaitForSingleObject(
-            HANDLE hHandle,
-            int dwMilliseconds
-    );
-
-    int GetLastError();
-}
diff --git a/main-command/src/main/java/sbt/internal/NGWin32NamedPipeServerSocket.java b/main-command/src/main/java/sbt/internal/NGWin32NamedPipeServerSocket.java
deleted file mode 100644
index 137d9b5dc..000000000
--- a/main-command/src/main/java/sbt/internal/NGWin32NamedPipeServerSocket.java
+++ /dev/null
@@ -1,173 +0,0 @@
-// Copied from https://github.com/facebook/nailgun/blob/af623fddedfdca010df46302a0711ce0e2cc1ba6/nailgun-server/src/main/java/com/martiansoftware/nailgun/NGWin32NamedPipeServerSocket.java
-
-/*
-
- Copyright 2004-2017, Martian Software, Inc.
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
-
- */
-package sbt.internal;
-
-import com.sun.jna.platform.win32.WinBase;
-import com.sun.jna.platform.win32.WinError;
-import com.sun.jna.platform.win32.WinNT;
-import com.sun.jna.platform.win32.WinNT.HANDLE;
-import com.sun.jna.ptr.IntByReference;
-
-import java.io.IOException;
-import java.net.ServerSocket;
-import java.net.Socket;
-import java.net.SocketAddress;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.LinkedBlockingQueue;
-
-public class NGWin32NamedPipeServerSocket extends ServerSocket {
-    private static final NGWin32NamedPipeLibrary API = NGWin32NamedPipeLibrary.INSTANCE;
-    private static final String WIN32_PIPE_PREFIX = "\\\\.\\pipe\\";
-    private static final int BUFFER_SIZE = 65535;
-    private final LinkedBlockingQueue<HANDLE> openHandles;
-    private final LinkedBlockingQueue<HANDLE> connectedHandles;
-    private final NGWin32NamedPipeSocket.CloseCallback closeCallback;
-    private final String path;
-    private final int maxInstances;
-    private final HANDLE lockHandle;
-
-    public NGWin32NamedPipeServerSocket(String path) throws IOException {
-        this(NGWin32NamedPipeLibrary.PIPE_UNLIMITED_INSTANCES, path);
-    }
-
-    public NGWin32NamedPipeServerSocket(int maxInstances, String path) throws IOException {
-        this.openHandles = new LinkedBlockingQueue<>();
-        this.connectedHandles = new LinkedBlockingQueue<>();
-        this.closeCallback = handle -> {
-            if (connectedHandles.remove(handle)) {
-                closeConnectedPipe(handle, false);
-            }
-            if (openHandles.remove(handle)) {
-                closeOpenPipe(handle);
-            }
-        };
-        this.maxInstances = maxInstances;
-        if (!path.startsWith(WIN32_PIPE_PREFIX)) {
-            this.path = WIN32_PIPE_PREFIX + path;
-        } else {
-            this.path = path;
-        }
-        String lockPath = this.path + "_lock";
-        lockHandle = API.CreateNamedPipe(
-                lockPath,
-                NGWin32NamedPipeLibrary.FILE_FLAG_FIRST_PIPE_INSTANCE | NGWin32NamedPipeLibrary.PIPE_ACCESS_DUPLEX,
-                0,
-                1,
-                BUFFER_SIZE,
-                BUFFER_SIZE,
-                0,
-                null);
-        if (lockHandle == NGWin32NamedPipeLibrary.INVALID_HANDLE_VALUE) {
-            throw new IOException(String.format("Could not create lock for %s, error %d", lockPath, API.GetLastError()));
-        } else {
-            if (!API.DisconnectNamedPipe(lockHandle)) {
-                throw new IOException(String.format("Could not disconnect lock %d", API.GetLastError()));
-            }
-        }
-
-    }
-
-    public void bind(SocketAddress endpoint) throws IOException {
-        throw new IOException("Win32 named pipes do not support bind(), pass path to constructor");
-    }
-
-    public Socket accept() throws IOException {
-        HANDLE handle = API.CreateNamedPipe(
-                path,
-                NGWin32NamedPipeLibrary.PIPE_ACCESS_DUPLEX | WinNT.FILE_FLAG_OVERLAPPED,
-                0,
-                maxInstances,
-                BUFFER_SIZE,
-                BUFFER_SIZE,
-                0,
-                null);
-        if (handle == NGWin32NamedPipeLibrary.INVALID_HANDLE_VALUE) {
-            throw new IOException(String.format("Could not create named pipe, error %d", API.GetLastError()));
-        }
-        openHandles.add(handle);
-
-        HANDLE connWaitable = API.CreateEvent(null, true, false, null);
-        WinBase.OVERLAPPED olap = new WinBase.OVERLAPPED();
-        olap.hEvent = connWaitable;
-        olap.write();
-
-        boolean immediate = API.ConnectNamedPipe(handle, olap.getPointer());
-        if (immediate) {
-            openHandles.remove(handle);
-            connectedHandles.add(handle);
-            return new NGWin32NamedPipeSocket(handle, closeCallback);
-        }
-
-        int connectError = API.GetLastError();
-        if (connectError == WinError.ERROR_PIPE_CONNECTED) {
-            openHandles.remove(handle);
-            connectedHandles.add(handle);
-            return new NGWin32NamedPipeSocket(handle, closeCallback);
-        } else if (connectError == WinError.ERROR_NO_DATA) {
-            // Client has connected and disconnected between CreateNamedPipe() and ConnectNamedPipe()
-            // connection is broken, but it is returned it avoid loop here.
-            // Actual error will happen for NGSession when it will try to read/write from/to pipe
-            return new NGWin32NamedPipeSocket(handle, closeCallback);
-        } else if (connectError == WinError.ERROR_IO_PENDING) {
-            if (!API.GetOverlappedResult(handle, olap.getPointer(), new IntByReference(), true)) {
-                openHandles.remove(handle);
-                closeOpenPipe(handle);
-                throw new IOException("GetOverlappedResult() failed for connect operation: " + API.GetLastError());
-            }
-            openHandles.remove(handle);
-            connectedHandles.add(handle);
-            return new NGWin32NamedPipeSocket(handle, closeCallback);
-        } else {
-            throw new IOException("ConnectNamedPipe() failed with: " + connectError);
-        }
-    }
-
-    public void close() throws IOException {
-        try {
-            List<HANDLE> handlesToClose = new ArrayList<>();
-            openHandles.drainTo(handlesToClose);
-            for (HANDLE handle : handlesToClose) {
-                closeOpenPipe(handle);
-            }
-
-            List<HANDLE> handlesToDisconnect = new ArrayList<>();
-            connectedHandles.drainTo(handlesToDisconnect);
-            for (HANDLE handle : handlesToDisconnect) {
-                closeConnectedPipe(handle, true);
-            }
-        } finally {
-            API.CloseHandle(lockHandle);
-        }
-    }
-
-    private void closeOpenPipe(HANDLE handle) throws IOException {
-        API.CancelIoEx(handle, null);
-        API.CloseHandle(handle);
-    }
-
-    private void closeConnectedPipe(HANDLE handle, boolean shutdown) throws IOException {
-        if (!shutdown) {
-            API.WaitForSingleObject(handle, 10000);
-        }
-        API.DisconnectNamedPipe(handle);
-        API.CloseHandle(handle);
-    }
-}
diff --git a/main-command/src/main/java/sbt/internal/NGWin32NamedPipeSocket.java b/main-command/src/main/java/sbt/internal/NGWin32NamedPipeSocket.java
deleted file mode 100644
index b22bb6bbf..000000000
--- a/main-command/src/main/java/sbt/internal/NGWin32NamedPipeSocket.java
+++ /dev/null
@@ -1,172 +0,0 @@
-// Copied from https://github.com/facebook/nailgun/blob/af623fddedfdca010df46302a0711ce0e2cc1ba6/nailgun-server/src/main/java/com/martiansoftware/nailgun/NGWin32NamedPipeSocket.java
-// Made change in `read` to read just the amount of bytes available.
-
-/*
-
- Copyright 2004-2017, Martian Software, Inc.
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
-
- */
-package sbt.internal;
-
-import com.sun.jna.Memory;
-import com.sun.jna.platform.win32.WinBase;
-import com.sun.jna.platform.win32.WinError;
-import com.sun.jna.platform.win32.WinNT.HANDLE;
-import com.sun.jna.ptr.IntByReference;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.net.Socket;
-import java.nio.ByteBuffer;
-
-public class NGWin32NamedPipeSocket extends Socket {
-    private static final NGWin32NamedPipeLibrary API = NGWin32NamedPipeLibrary.INSTANCE;
-    private final HANDLE handle;
-    private final CloseCallback closeCallback;
-    private final InputStream is;
-    private final OutputStream os;
-    private final HANDLE readerWaitable;
-    private final HANDLE writerWaitable;
-
-    interface CloseCallback {
-        void onNamedPipeSocketClose(HANDLE handle) throws IOException;
-    }
-
-    public NGWin32NamedPipeSocket(
-            HANDLE handle,
-            NGWin32NamedPipeSocket.CloseCallback closeCallback) throws IOException {
-        this.handle = handle;
-        this.closeCallback = closeCallback;
-        this.readerWaitable = API.CreateEvent(null, true, false, null);
-        if (readerWaitable == null) {
-            throw new IOException("CreateEvent() failed ");
-        }
-        writerWaitable = API.CreateEvent(null, true, false, null);
-        if (writerWaitable == null) {
-            throw new IOException("CreateEvent() failed ");
-        }
-        this.is = new NGWin32NamedPipeSocketInputStream(handle);
-        this.os = new NGWin32NamedPipeSocketOutputStream(handle);
-    }
-
-    @Override
-    public InputStream getInputStream() {
-        return is;
-    }
-
-    @Override
-    public OutputStream getOutputStream() {
-        return os;
-    }
-
-    @Override
-    public void close() throws IOException {
-        closeCallback.onNamedPipeSocketClose(handle);
-    }
-
-    @Override
-    public void shutdownInput() throws IOException {
-    }
-
-    @Override
-    public void shutdownOutput() throws IOException {
-    }
-
-    private class NGWin32NamedPipeSocketInputStream extends InputStream {
-        private final HANDLE handle;
-
-        NGWin32NamedPipeSocketInputStream(HANDLE handle) {
-            this.handle = handle;
-        }
-
-        @Override
-        public int read() throws IOException {
-            int result;
-            byte[] b = new byte[1];
-            if (read(b) == 0) {
-                result = -1;
-            } else {
-                result = 0xFF & b[0];
-            }
-            return result;
-        }
-
-        @Override
-        public int read(byte[] b, int off, int len) throws IOException {
-            Memory readBuffer = new Memory(len);
-
-            WinBase.OVERLAPPED olap = new WinBase.OVERLAPPED();
-            olap.hEvent = readerWaitable;
-            olap.write();
-
-            boolean immediate = API.ReadFile(handle, readBuffer, len, null, olap.getPointer());
-            if (!immediate) {
-                int lastError = API.GetLastError();
-                if (lastError != WinError.ERROR_IO_PENDING) {
-                    throw new IOException("ReadFile() failed: " + lastError);
-                }
-            }
-
-            IntByReference read = new IntByReference();
-            if (!API.GetOverlappedResult(handle, olap.getPointer(), read, true)) {
-                int lastError = API.GetLastError();
-                throw new IOException("GetOverlappedResult() failed for read operation: " + lastError);
-            }
-            int actualLen = read.getValue();
-            byte[] byteArray = readBuffer.getByteArray(0, actualLen);
-            System.arraycopy(byteArray, 0, b, off, actualLen);
-            return actualLen;
-        }
-    }
-
-    private class NGWin32NamedPipeSocketOutputStream extends OutputStream {
-        private final HANDLE handle;
-
-        NGWin32NamedPipeSocketOutputStream(HANDLE handle) {
-            this.handle = handle;
-        }
-
-        @Override
-        public void write(int b) throws IOException {
-            write(new byte[]{(byte) (0xFF & b)});
-        }
-
-        @Override
-        public void write(byte[] b, int off, int len) throws IOException {
-            ByteBuffer data = ByteBuffer.wrap(b, off, len);
-
-            WinBase.OVERLAPPED olap = new WinBase.OVERLAPPED();
-            olap.hEvent = writerWaitable;
-            olap.write();
-
-            boolean immediate = API.WriteFile(handle, data, len, null, olap.getPointer());
-            if (!immediate) {
-                int lastError = API.GetLastError();
-                if (lastError != WinError.ERROR_IO_PENDING) {
-                    throw new IOException("WriteFile() failed: " + lastError);
-                }
-            }
-            IntByReference written = new IntByReference();
-            if (!API.GetOverlappedResult(handle, olap.getPointer(), written, true)) {
-                int lastError = API.GetLastError();
-                throw new IOException("GetOverlappedResult() failed for write operation: " + lastError);
-            }
-            if (written.getValue() != len) {
-                throw new IOException("WriteFile() wrote less bytes than requested");
-            }
-        }
-    }
-}
diff --git a/main-command/src/main/java/sbt/internal/ReferenceCountedFileDescriptor.java b/main-command/src/main/java/sbt/internal/ReferenceCountedFileDescriptor.java
deleted file mode 100644
index 7fb5d9d53..000000000
--- a/main-command/src/main/java/sbt/internal/ReferenceCountedFileDescriptor.java
+++ /dev/null
@@ -1,82 +0,0 @@
-// Copied from https://github.com/facebook/nailgun/blob/af623fddedfdca010df46302a0711ce0e2cc1ba6/nailgun-server/src/main/java/com/martiansoftware/nailgun/ReferenceCountedFileDescriptor.java
-
-/*
-
- Copyright 2004-2015, Martian Software, Inc.
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
-
- */
-package sbt.internal;
-
-import com.sun.jna.LastErrorException;
-
-import java.io.IOException;
-
-/**
- * Encapsulates a file descriptor plus a reference count to ensure close requests
- * only close the file descriptor once the last reference to the file descriptor
- * is released.
- *
- * If not explicitly closed, the file descriptor will be closed when
- * this object is finalized.
- */
-public class ReferenceCountedFileDescriptor {
-  private int fd;
-  private int fdRefCount;
-  private boolean closePending;
-
-  public ReferenceCountedFileDescriptor(int fd) {
-    this.fd = fd;
-    this.fdRefCount = 0;
-    this.closePending = false;
-  }
-
-  protected void finalize() throws IOException {
-    close();
-  }
-
-  public synchronized int acquire() {
-    fdRefCount++;
-    return fd;
-  }
-
-  public synchronized void release() throws IOException {
-    fdRefCount--;
-    if (fdRefCount == 0 && closePending && fd != -1) {
-      doClose();
-    }
-  }
-
-  public synchronized void close() throws IOException {
-    if (fd == -1 || closePending) {
-      return;
-    }
-
-    if (fdRefCount == 0) {
-      doClose();
-    } else {
-      // Another thread has the FD. We'll close it when they release the reference.
-      closePending = true;
-    }
-  }
-
-  private void doClose() throws IOException {
-    try {
-      NGUnixDomainSocketLibrary.close(fd);
-      fd = -1;
-    } catch (LastErrorException e) {
-      throw new IOException(e);
-    }
-  }
-}
diff --git a/main-command/src/main/scala/sbt/internal/server/Server.scala b/main-command/src/main/scala/sbt/internal/server/Server.scala
index 8104a1736..7e31910e6 100644
--- a/main-command/src/main/scala/sbt/internal/server/Server.scala
+++ b/main-command/src/main/scala/sbt/internal/server/Server.scala
@@ -25,6 +25,7 @@ import sjsonnew.support.scalajson.unsafe.{ Converter, CompactPrinter }
 import sbt.internal.protocol.codec._
 import sbt.internal.util.ErrorHandling
 import sbt.internal.util.Util.isWindows
+import org.scalasbt.ipcsocket._
 
 private[sbt] sealed trait ServerInstance {
   def shutdown(): Unit
@@ -57,11 +58,11 @@ private[sbt] object Server {
             connection.connectionType match {
               case ConnectionType.Local if isWindows =>
                 // Named pipe already has an exclusive lock.
-                addServerError(new NGWin32NamedPipeServerSocket(pipeName))
+                addServerError(new Win32NamedPipeServerSocket(pipeName))
               case ConnectionType.Local =>
-                tryClient(new NGUnixDomainSocket(socketfile.getAbsolutePath))
+                tryClient(new UnixDomainSocket(socketfile.getAbsolutePath))
                 prepareSocketfile()
-                addServerError(new NGUnixDomainServerSocket(socketfile.getAbsolutePath))
+                addServerError(new UnixDomainServerSocket(socketfile.getAbsolutePath))
               case ConnectionType.Tcp =>
                 tryClient(new Socket(InetAddress.getByName(host), port))
                 addServerError(new ServerSocket(port, 50, InetAddress.getByName(host)))
diff --git a/main/src/main/scala/sbt/internal/CommandExchange.scala b/main/src/main/scala/sbt/internal/CommandExchange.scala
index 2ece2e12a..094491945 100644
--- a/main/src/main/scala/sbt/internal/CommandExchange.scala
+++ b/main/src/main/scala/sbt/internal/CommandExchange.scala
@@ -114,7 +114,7 @@ private[sbt] final class CommandExchange {
       subscribe(channel)
     }
     if (server.isEmpty && firstInstance.get) {
-      val portfile = (new File(".")).getAbsoluteFile / "project" / "target" / "active.json"
+      val portfile = s.baseDir / "project" / "target" / "active.json"
       val h = Hash.halfHashString(IO.toURI(portfile).toString)
       val tokenfile = BuildPaths.getGlobalBase(s) / "server" / h / "token.json"
       val socketfile = BuildPaths.getGlobalBase(s) / "server" / h / "sock"
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index f8d470ccd..5ad8a4393 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -33,6 +33,7 @@ object Dependencies {
   val launcherInterface = "org.scala-sbt" % "launcher-interface" % "1.0.2"
   val rawLauncher = "org.scala-sbt" % "launcher" % "1.0.2"
   val testInterface = "org.scala-sbt" % "test-interface" % "1.0"
+  val ipcSocket = "org.scala-sbt.ipcsocket" % "ipcsocket" % "1.0.0"
 
   private val compilerInterface = "org.scala-sbt" % "compiler-interface" % zincVersion
   private val compilerClasspath = "org.scala-sbt" %% "zinc-classpath" % zincVersion
diff --git a/protocol/src/main/scala/sbt/protocol/ClientSocket.scala b/protocol/src/main/scala/sbt/protocol/ClientSocket.scala
new file mode 100644
index 000000000..df155d439
--- /dev/null
+++ b/protocol/src/main/scala/sbt/protocol/ClientSocket.scala
@@ -0,0 +1,45 @@
+/*
+ * sbt
+ * Copyright 2011 - 2017, Lightbend, Inc.
+ * Copyright 2008 - 2010, Mark Harrah
+ * Licensed under BSD-3-Clause license (see LICENSE)
+ */
+
+package sbt
+package protocol
+
+import java.io.File
+import java.net.{ Socket, URI, InetAddress }
+import sjsonnew.BasicJsonProtocol
+import sjsonnew.support.scalajson.unsafe.{ Parser, Converter }
+import sjsonnew.shaded.scalajson.ast.unsafe.JValue
+import sbt.internal.protocol.{ PortFile, TokenFile }
+import sbt.internal.protocol.codec.{ PortFileFormats, TokenFileFormats }
+import sbt.internal.util.Util.isWindows
+import org.scalasbt.ipcsocket._
+
+object ClientSocket {
+  private lazy val fileFormats = new BasicJsonProtocol with PortFileFormats with TokenFileFormats {}
+
+  def socket(portfile: File): (Socket, Option[String]) = {
+    import fileFormats._
+    val json: JValue = Parser.parseFromFile(portfile).get
+    val p = Converter.fromJson[PortFile](json).get
+    val uri = new URI(p.uri)
+    // println(uri)
+    val token = p.tokenfilePath map { tp =>
+      val tokeFile = new File(tp)
+      val json: JValue = Parser.parseFromFile(tokeFile).get
+      val t = Converter.fromJson[TokenFile](json).get
+      t.token
+    }
+    val sk = uri.getScheme match {
+      case "local" if isWindows =>
+        new Win32NamedPipeSocket("""\\.\pipe\""" + uri.getSchemeSpecificPart)
+      case "local" => new UnixDomainSocket(uri.getSchemeSpecificPart)
+      case "tcp"   => new Socket(InetAddress.getByName(uri.getHost), uri.getPort)
+      case _       => sys.error(s"Unsupported uri: $uri")
+    }
+    (sk, token)
+  }
+}
diff --git a/sbt/src/sbt-test/server/handshake/Client.scala b/sbt/src/sbt-test/server/handshake/Client.scala
deleted file mode 100644
index 2f41f4c18..000000000
--- a/sbt/src/sbt-test/server/handshake/Client.scala
+++ /dev/null
@@ -1,106 +0,0 @@
-package example
-
-import java.net.{ URI, Socket, InetAddress, SocketException }
-import sbt.io._
-import sbt.io.syntax._
-import java.io.File
-import sjsonnew.support.scalajson.unsafe.{ Parser, Converter, CompactPrinter }
-import sjsonnew.shaded.scalajson.ast.unsafe.{ JValue, JObject, JString }
-
-object Client extends App {
-  val host = "127.0.0.1"
-  val delimiter: Byte = '\n'.toByte
-
-  lazy val connection = getConnection
-  lazy val out = connection.getOutputStream
-  lazy val in = connection.getInputStream
-
-  val t = getToken
-  val msg0 = s"""{ "type": "InitCommand", "token": "$t" }"""
-
-  writeLine(s"Content-Length: ${ msg0.size + 2 }")
-  writeLine("Content-Type: application/sbt-x1")
-  writeLine("")
-  writeLine(msg0)
-  out.flush
-
-  writeLine("Content-Length: 49")
-  writeLine("Content-Type: application/sbt-x1")
-  writeLine("")
-            // 12345678901234567890123456789012345678901234567890
-  writeLine("""{ "type": "ExecCommand", "commandLine": "exit" }""")
-  writeLine("")
-  out.flush
-
-  val baseDirectory = new File(args(0))
-  IO.write(baseDirectory / "ok.txt", "ok")
-
-  def getToken: String = {
-    val tokenfile = new File(getTokenFileUri)
-    val json: JValue = Parser.parseFromFile(tokenfile).get
-    json match {
-      case JObject(fields) =>
-        (fields find { _.field == "token" } map { _.value }) match {
-          case Some(JString(value)) => value
-          case _                    =>
-            sys.error("json doesn't token field that is JString")
-        }
-      case _ => sys.error("json doesn't have token field")
-    }
-  }
-
-  def getTokenFileUri: URI = {
-    val portfile = baseDirectory / "project" / "target" / "active.json"
-    val json: JValue = Parser.parseFromFile(portfile).get
-    json match {
-      case JObject(fields) =>
-        (fields find { _.field == "tokenfileUri" } map { _.value }) match {
-          case Some(JString(value)) => new URI(value)
-          case _                    =>
-            sys.error("json doesn't tokenfile field that is JString")
-        }
-      case _ => sys.error("json doesn't have tokenfile field")
-    }
-  }
-
-  def getPort: Int = {
-    val portfile = baseDirectory / "project" / "target" / "active.json"
-    val json: JValue = Parser.parseFromFile(portfile).get
-    json match {
-      case JObject(fields) =>
-        (fields find { _.field == "uri" } map { _.value }) match {
-          case Some(JString(value)) => 
-            val u = new URI(value)
-            u.getPort
-          case _                    =>
-            sys.error("json doesn't uri field that is JString")
-        }
-      case _ => sys.error("json doesn't have uri field")
-    }
-  }
-
-  def getConnection: Socket =
-    try {
-      new Socket(InetAddress.getByName(host), getPort)
-    } catch {
-      case _ =>
-        Thread.sleep(1000)
-        getConnection
-    }
-
-  def writeLine(s: String): Unit = {
-    if (s != "") {
-      out.write(s.getBytes("UTF-8"))
-    }
-    writeEndLine
-  }
-
-  def writeEndLine(): Unit = {
-    val retByte: Byte = '\r'.toByte
-    val delimiter: Byte = '\n'.toByte
-
-    out.write(retByte.toInt)
-    out.write(delimiter.toInt)
-    out.flush
-  }
-}
diff --git a/sbt/src/sbt-test/server/handshake/build.sbt b/sbt/src/sbt-test/server/handshake/build.sbt
deleted file mode 100644
index 851648f3c..000000000
--- a/sbt/src/sbt-test/server/handshake/build.sbt
+++ /dev/null
@@ -1,15 +0,0 @@
-lazy val runClient = taskKey[Unit]("")
-
-lazy val root = (project in file("."))
-  .settings(
-    serverConnectionType in Global := ConnectionType.Tcp,
-    scalaVersion := "2.12.3",
-    serverPort in Global := 5123,
-    libraryDependencies += "org.scala-sbt" %% "io" % "1.0.1",
-    libraryDependencies += "com.eed3si9n" %%  "sjson-new-scalajson" % "0.8.0",
-    runClient := (Def.taskDyn {
-      val b = baseDirectory.value
-      (bgRun in Compile).toTask(s""" $b""")
-    }).value
-  )
- 
\ No newline at end of file
diff --git a/sbt/src/sbt-test/server/handshake/test b/sbt/src/sbt-test/server/handshake/test
deleted file mode 100644
index 703942376..000000000
--- a/sbt/src/sbt-test/server/handshake/test
+++ /dev/null
@@ -1,6 +0,0 @@
-> show serverPort
-> runClient
-
--> shell
-
-$ exists ok.txt
diff --git a/sbt/src/server-test/handshake/build.sbt b/sbt/src/server-test/handshake/build.sbt
new file mode 100644
index 000000000..192730eef
--- /dev/null
+++ b/sbt/src/server-test/handshake/build.sbt
@@ -0,0 +1,6 @@
+lazy val root = (project in file("."))
+  .settings(
+    Global / serverLog / logLevel := Level.Debug,
+    name := "handshake",
+    scalaVersion := "2.12.3",
+  )
diff --git a/sbt/src/test/scala/sbt/RunFromSourceMain.scala b/sbt/src/test/scala/sbt/RunFromSourceMain.scala
index bd2f142f7..b4fc8bce4 100644
--- a/sbt/src/test/scala/sbt/RunFromSourceMain.scala
+++ b/sbt/src/test/scala/sbt/RunFromSourceMain.scala
@@ -22,7 +22,7 @@ object RunFromSourceMain {
 
   // this arrangement is because Scala does not always properly optimize away
   // the tail recursion in a catch statement
-  @tailrec private def run(baseDir: File, args: Seq[String]): Unit =
+  @tailrec private[sbt] def run(baseDir: File, args: Seq[String]): Unit =
     runImpl(baseDir, args) match {
       case Some((baseDir, args)) => run(baseDir, args)
       case None                  => ()
diff --git a/sbt/src/test/scala/sbt/ServerSpec.scala b/sbt/src/test/scala/sbt/ServerSpec.scala
new file mode 100644
index 000000000..648d88203
--- /dev/null
+++ b/sbt/src/test/scala/sbt/ServerSpec.scala
@@ -0,0 +1,179 @@
+/*
+ * sbt
+ * Copyright 2011 - 2017, Lightbend, Inc.
+ * Copyright 2008 - 2010, Mark Harrah
+ * Licensed under BSD-3-Clause license (see LICENSE)
+ */
+
+package sbt
+
+import org.scalatest._
+import scala.concurrent._
+import java.io.{ InputStream, OutputStream }
+import java.util.concurrent.atomic.AtomicInteger
+import java.util.concurrent.{ ThreadFactory, ThreadPoolExecutor }
+import sbt.protocol.ClientSocket
+
+class ServerSpec extends AsyncFlatSpec with Matchers {
+  import ServerSpec._
+
+  "server" should "start" in {
+    withBuildSocket("handshake") { (out, in, tkn) =>
+      writeLine(
+        """{ "jsonrpc": "2.0", "id": 3, "method": "sbt/setting", "params": { "setting": "root/name" } }""",
+        out)
+      Thread.sleep(100)
+      val l2 = contentLength(in)
+      println(l2)
+      readLine(in)
+      readLine(in)
+      val x2 = readContentLength(in, l2)
+      println(x2)
+      assert(1 == 1)
+    }
+  }
+}
+
+object ServerSpec {
+  private val serverTestBase: File = new File(".").getAbsoluteFile / "sbt" / "src" / "server-test"
+  private val nextThreadId = new AtomicInteger(1)
+  private val threadGroup = Thread.currentThread.getThreadGroup()
+  val readBuffer = new Array[Byte](4096)
+  var buffer: Vector[Byte] = Vector.empty
+  var bytesRead = 0
+  private val delimiter: Byte = '\n'.toByte
+  private val RetByte = '\r'.toByte
+
+  private val threadFactory = new ThreadFactory() {
+    override def newThread(runnable: Runnable): Thread = {
+      val thread =
+        new Thread(threadGroup,
+                   runnable,
+                   s"sbt-test-server-threads-${nextThreadId.getAndIncrement}")
+      // Do NOT setDaemon because then the code in TaskExit.scala in sbt will insta-kill
+      // the backgrounded process, at least for the case of the run task.
+      thread
+    }
+  }
+
+  private val executor = new ThreadPoolExecutor(
+    0, /* corePoolSize */
+    1, /* maxPoolSize, max # of servers */
+    2,
+    java.util.concurrent.TimeUnit.SECONDS,
+    /* keep alive unused threads this long (if corePoolSize < maxPoolSize) */
+    new java.util.concurrent.SynchronousQueue[Runnable](),
+    threadFactory
+  )
+
+  def backgroundRun(baseDir: File, args: Seq[String]): Unit = {
+    executor.execute(new Runnable {
+      def run(): Unit = {
+        RunFromSourceMain.run(baseDir, args)
+      }
+    })
+  }
+
+  def shutdown(): Unit = executor.shutdown()
+
+  def withBuildSocket(testBuild: String)(
+      f: (OutputStream, InputStream, Option[String]) => Future[Assertion]): Future[Assertion] = {
+    IO.withTemporaryDirectory { temp =>
+      IO.copyDirectory(serverTestBase / testBuild, temp / testBuild)
+      withBuildSocket(temp / testBuild)(f)
+    }
+  }
+
+  def sendJsonRpc(message: String, out: OutputStream): Unit = {
+    writeLine(s"""Content-Length: ${message.size + 2}""", out)
+    writeLine("", out)
+    writeLine(message, out)
+  }
+
+  def contentLength(in: InputStream): Int = {
+    readLine(in) map { line =>
+      line.drop(16).toInt
+    } getOrElse (0)
+  }
+
+  def readLine(in: InputStream): Option[String] = {
+    if (buffer.isEmpty) {
+      val bytesRead = in.read(readBuffer)
+      if (bytesRead > 0) {
+        buffer = buffer ++ readBuffer.toVector.take(bytesRead)
+      }
+    }
+    val delimPos = buffer.indexOf(delimiter)
+    if (delimPos > 0) {
+      val chunk0 = buffer.take(delimPos)
+      buffer = buffer.drop(delimPos + 1)
+      // remove \r at the end of line.
+      if (chunk0.size > 0 && chunk0.indexOf(RetByte) == chunk0.size - 1)
+        Some(new String(chunk0.dropRight(1).toArray, "utf-8"))
+      else Some(new String(chunk0.toArray, "utf-8"))
+    } else None // no EOL yet, so skip this turn.
+  }
+
+  def readContentLength(in: InputStream, length: Int): Option[String] = {
+    if (buffer.isEmpty) {
+      val bytesRead = in.read(readBuffer)
+      if (bytesRead > 0) {
+        buffer = buffer ++ readBuffer.toVector.take(bytesRead)
+      }
+    }
+    if (length <= buffer.size) {
+      val chunk = buffer.take(length)
+      buffer = buffer.drop(length)
+      Some(new String(chunk.toArray, "utf-8"))
+    } else None // have not read enough yet, so skip this turn.
+  }
+
+  def writeLine(s: String, out: OutputStream): Unit = {
+    def writeEndLine(): Unit = {
+      val retByte: Byte = '\r'.toByte
+      val delimiter: Byte = '\n'.toByte
+      out.write(retByte.toInt)
+      out.write(delimiter.toInt)
+      out.flush
+    }
+
+    if (s != "") {
+      out.write(s.getBytes("UTF-8"))
+    }
+    writeEndLine
+  }
+
+  def withBuildSocket(baseDirectory: File)(
+      f: (OutputStream, InputStream, Option[String]) => Future[Assertion]): Future[Assertion] = {
+    backgroundRun(baseDirectory, Nil)
+
+    val portfile = baseDirectory / "project" / "target" / "active.json"
+
+    def waitForPortfile(n: Int): Unit =
+      if (portfile.exists) ()
+      else {
+        if (n <= 0) sys.error(s"Timeout. $portfile is not found.")
+        else {
+          Thread.sleep(1000)
+          waitForPortfile(n - 1)
+        }
+      }
+    waitForPortfile(10)
+    val (sk, tkn) = ClientSocket.socket(portfile)
+    val out = sk.getOutputStream
+    val in = sk.getInputStream
+
+    sendJsonRpc(
+      """{ "jsonrpc": "2.0", "id": 1, "method": "initialize", "params": { "initializationOptions": { } } }""",
+      out)
+
+    try {
+      f(out, in, tkn)
+    } finally {
+      sendJsonRpc(
+        """{ "jsonrpc": "2.0", "id": 9, "method": "sbt/exec", "params": { "commandLine": "exit" } }""",
+        out)
+      shutdown()
+    }
+  }
+}