diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 994e17a23..c947404ad 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,3 +1,13 @@
 ```
 $ sbt release
 ```
+
+### Historical note
+
+```
+cd sbt-modules/util-take2
+git filter-branch --index-filter 'git rm --cached -qr -- . && git reset -q $GIT_COMMIT -- build.sbt LICENSE NOTICE interface util/appmacro util/collection util/complete util/control util/log util/logic util/process util/relation cache' --prune-empty
+git reset --hard
+git gc --aggressive
+git prune
+```
diff --git a/README.md b/README.md
index acdbb8c3a..87ddd558f 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1 @@
 ### utility modules for sbt
-
-```
-cd sbt-modules/util-take2
-git filter-branch --index-filter 'git rm --cached -qr -- . && git reset -q $GIT_COMMIT -- build.sbt LICENSE NOTICE interface util/appmacro util/collection util/complete util/control util/log util/logic util/process util/relation cache' --prune-empty
-git reset --hard
-git gc --aggressive
-git prune
-```
diff --git a/build.sbt b/build.sbt
index 78c9048f4..eb9ede57b 100644
--- a/build.sbt
+++ b/build.sbt
@@ -127,23 +127,21 @@ lazy val utilLogic = (project in internalPath / "util-logic").
   )
 
 // Persisted caching based on sjson-new
-lazy val utilCache = (project in internalPath / "util-cache").
+lazy val utilCache = (project in file("util-cache")).
   dependsOn(utilCollection, utilTesting % Test).
   settings(
     commonSettings,
     name := "Util Cache",
-    libraryDependencies ++= Seq(sjsonnew, scalaReflect.value),
-    libraryDependencies += sjsonnewScalaJson % Test
+    libraryDependencies ++= Seq(sjsonnewScalaJson, scalaReflect.value)
   ).
   configure(addSbtIO)
 
 // Builds on cache to provide caching for filesystem-related operations
-lazy val utilTracking = (project in internalPath / "util-tracking").
+lazy val utilTracking = (project in file("util-tracking")).
   dependsOn(utilCache, utilTesting % Test).
   settings(
     commonSettings,
-    name := "Util Tracking",
-    libraryDependencies += sjsonnewScalaJson % Test
+    name := "Util Tracking"
   ).
   configure(addSbtIO)
 
diff --git a/internal/util-cache/src/main/scala/sbt/internal/util/CacheImplicits.scala b/internal/util-cache/src/main/scala/sbt/internal/util/CacheImplicits.scala
deleted file mode 100644
index 00bb6beaa..000000000
--- a/internal/util-cache/src/main/scala/sbt/internal/util/CacheImplicits.scala
+++ /dev/null
@@ -1,7 +0,0 @@
-package sbt.internal.util
-
-import sjsonnew.BasicJsonProtocol
-
-object CacheImplicits extends BasicCacheImplicits
-  with BasicJsonProtocol
-  with HListFormat
diff --git a/project/build.properties b/project/build.properties
index 27e88aa11..64317fdae 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -1 +1 @@
-sbt.version=0.13.13
+sbt.version=0.13.15
diff --git a/internal/util-cache/NOTICE b/util-cache/NOTICE
similarity index 100%
rename from internal/util-cache/NOTICE
rename to util-cache/NOTICE
diff --git a/internal/util-cache/src/main/scala/sbt/internal/util/HListFormat.scala b/util-cache/src/main/scala/sbt/internal/util/HListFormats.scala
similarity index 97%
rename from internal/util-cache/src/main/scala/sbt/internal/util/HListFormat.scala
rename to util-cache/src/main/scala/sbt/internal/util/HListFormats.scala
index 6594896c8..bf69b4db8 100644
--- a/internal/util-cache/src/main/scala/sbt/internal/util/HListFormat.scala
+++ b/util-cache/src/main/scala/sbt/internal/util/HListFormats.scala
@@ -1,9 +1,11 @@
-package sbt.internal.util
+package sbt
+package internal
+package util
 
 import sjsonnew._
 import Types.:+:
 
-trait HListFormat {
+trait HListFormats {
   implicit val lnilFormat1: JsonFormat[HNil] = forHNil(HNil)
   implicit val lnilFormat2: JsonFormat[HNil.type] = forHNil(HNil)
 
diff --git a/internal/util-cache/src/main/scala/sbt/internal/util/BasicCacheImplicits.scala b/util-cache/src/main/scala/sbt/util/BasicCacheImplicits.scala
similarity index 98%
rename from internal/util-cache/src/main/scala/sbt/internal/util/BasicCacheImplicits.scala
rename to util-cache/src/main/scala/sbt/util/BasicCacheImplicits.scala
index 1d1ebe16d..92e69bddb 100644
--- a/internal/util-cache/src/main/scala/sbt/internal/util/BasicCacheImplicits.scala
+++ b/util-cache/src/main/scala/sbt/util/BasicCacheImplicits.scala
@@ -1,4 +1,4 @@
-package sbt.internal.util
+package sbt.util
 
 import java.net.{ URI, URL }
 
diff --git a/internal/util-cache/src/main/scala/sbt/internal/util/Cache.scala b/util-cache/src/main/scala/sbt/util/Cache.scala
similarity index 82%
rename from internal/util-cache/src/main/scala/sbt/internal/util/Cache.scala
rename to util-cache/src/main/scala/sbt/util/Cache.scala
index 0a04dbcdd..3b85a8dc2 100644
--- a/internal/util-cache/src/main/scala/sbt/internal/util/Cache.scala
+++ b/util-cache/src/main/scala/sbt/util/Cache.scala
@@ -1,7 +1,9 @@
 /* sbt -- Simple Build Tool
  * Copyright 2009 Mark Harrah
  */
-package sbt.internal.util
+package sbt.util
+
+import java.io.File
 
 /** The result of a cache query */
 sealed trait CacheResult[K]
@@ -32,6 +34,15 @@ object Cache {
    */
   def cache[I, O](implicit c: Cache[I, O]): Cache[I, O] = c
 
+  /**
+   * Returns a function that represents a cache that inserts on miss.
+   *
+   * @param cacheFile The store that backs this cache.
+   * @param default   A function that computes a default value to insert on
+   */
+  def cached[I, O](cacheFile: File)(default: I => O)(implicit cache: Cache[I, O]): I => O =
+    cached(CacheStore(cacheFile))(default)
+
   /**
    * Returns a function that represents a cache that inserts on miss.
    *
diff --git a/util-cache/src/main/scala/sbt/util/CacheImplicits.scala b/util-cache/src/main/scala/sbt/util/CacheImplicits.scala
new file mode 100644
index 000000000..2eb1639cd
--- /dev/null
+++ b/util-cache/src/main/scala/sbt/util/CacheImplicits.scala
@@ -0,0 +1,9 @@
+package sbt.util
+
+import sjsonnew.BasicJsonProtocol
+import sbt.internal.util.HListFormats
+
+object CacheImplicits extends CacheImplicits
+trait CacheImplicits extends BasicCacheImplicits
+  with BasicJsonProtocol
+  with HListFormats
diff --git a/internal/util-cache/src/main/scala/sbt/internal/util/CacheStore.scala b/util-cache/src/main/scala/sbt/util/CacheStore.scala
similarity index 55%
rename from internal/util-cache/src/main/scala/sbt/internal/util/CacheStore.scala
rename to util-cache/src/main/scala/sbt/util/CacheStore.scala
index c7e2674b7..073a52281 100644
--- a/internal/util-cache/src/main/scala/sbt/internal/util/CacheStore.scala
+++ b/util-cache/src/main/scala/sbt/util/CacheStore.scala
@@ -1,30 +1,55 @@
-package sbt.internal.util
+package sbt.util
 
 import java.io.{ File, InputStream, OutputStream }
 import sbt.io.syntax.fileToRichFile
 import sbt.io.{ IO, Using }
 import sjsonnew.{ IsoString, JsonReader, JsonWriter, SupportConverter }
+import sjsonnew.support.scalajson.unsafe.{ CompactPrinter, Converter, Parser }
+import scala.json.ast.unsafe.JValue
 
 /** A `CacheStore` is used by the caching infrastructure to persist cached information. */
-trait CacheStore extends Input with Output {
+abstract class CacheStore extends Input with Output {
   /** Delete the persisted information. */
   def delete(): Unit
 }
 
-/** Factory that can derive new stores. */
-trait CacheStoreFactory {
+object CacheStore {
+  implicit lazy val jvalueIsoString: IsoString[JValue] = IsoString.iso(CompactPrinter.apply, Parser.parseUnsafe)
+
+  /** Returns file-based CacheStore using standard JSON converter. */
+  def apply(cacheFile: File): CacheStore = file(cacheFile)
+
+  /** Returns file-based CacheStore using standard JSON converter. */
+  def file(cacheFile: File): CacheStore = new FileBasedStore[JValue](cacheFile, Converter)
+}
+
+/** Factory that can make new stores. */
+abstract class CacheStoreFactory {
   /** Create a new store. */
-  def derive(identifier: String): CacheStore
+  def make(identifier: String): CacheStore
 
   /** Create a new `CacheStoreFactory` from this factory. */
   def sub(identifier: String): CacheStoreFactory
+
+  /** A symbolic alias for `sub`. */
+  final def /(identifier: String): CacheStoreFactory = sub(identifier)
+}
+
+object CacheStoreFactory {
+  implicit lazy val jvalueIsoString: IsoString[JValue] = IsoString.iso(CompactPrinter.apply, Parser.parseUnsafe)
+
+  /** Returns directory-based CacheStoreFactory using standard JSON converter. */
+  def apply(base: File): CacheStoreFactory = directory(base)
+
+  /** Returns directory-based CacheStoreFactory using standard JSON converter. */
+  def directory(base: File): CacheStoreFactory = new DirectoryStoreFactory[JValue](base, Converter)
 }
 
 /** A factory that creates new stores persisted in `base`. */
 class DirectoryStoreFactory[J: IsoString](base: File, converter: SupportConverter[J]) extends CacheStoreFactory {
   IO.createDirectory(base)
 
-  def derive(identifier: String): CacheStore = new FileBasedStore(base / identifier, converter)
+  def make(identifier: String): CacheStore = new FileBasedStore(base / identifier, converter)
 
   def sub(identifier: String): CacheStoreFactory = new DirectoryStoreFactory(base / identifier, converter)
 }
diff --git a/internal/util-cache/src/main/scala/sbt/internal/util/FileInfo.scala b/util-cache/src/main/scala/sbt/util/FileInfo.scala
similarity index 96%
rename from internal/util-cache/src/main/scala/sbt/internal/util/FileInfo.scala
rename to util-cache/src/main/scala/sbt/util/FileInfo.scala
index 5f4a3fd1e..6c42422d0 100644
--- a/internal/util-cache/src/main/scala/sbt/internal/util/FileInfo.scala
+++ b/util-cache/src/main/scala/sbt/util/FileInfo.scala
@@ -1,7 +1,7 @@
 /* sbt -- Simple Build Tool
  * Copyright 2009 Mark Harrah
  */
-package sbt.internal.util
+package sbt.util
 
 import java.io.File
 import scala.util.control.NonFatal
@@ -40,6 +40,11 @@ object FilesInfo {
 
   implicit def format[F <: FileInfo: JsonFormat]: JsonFormat[FilesInfo[F]] =
     project(_.files, (fs: Set[F]) => FilesInfo(fs))
+
+  def full: FileInfo.Style = FileInfo.full
+  def hash: FileInfo.Style = FileInfo.hash
+  def lastModified: FileInfo.Style = FileInfo.lastModified
+  def exists: FileInfo.Style = FileInfo.exists
 }
 
 object FileInfo {
diff --git a/internal/util-cache/src/main/scala/sbt/internal/util/Input.scala b/util-cache/src/main/scala/sbt/util/Input.scala
similarity index 97%
rename from internal/util-cache/src/main/scala/sbt/internal/util/Input.scala
rename to util-cache/src/main/scala/sbt/util/Input.scala
index 3426c117d..646660e59 100644
--- a/internal/util-cache/src/main/scala/sbt/internal/util/Input.scala
+++ b/util-cache/src/main/scala/sbt/util/Input.scala
@@ -1,4 +1,4 @@
-package sbt.internal.util
+package sbt.util
 
 import java.io.{ Closeable, InputStream }
 import scala.util.control.NonFatal
diff --git a/internal/util-cache/src/main/scala/sbt/internal/util/Output.scala b/util-cache/src/main/scala/sbt/util/Output.scala
similarity index 96%
rename from internal/util-cache/src/main/scala/sbt/internal/util/Output.scala
rename to util-cache/src/main/scala/sbt/util/Output.scala
index 0472adee4..cf4b27f12 100644
--- a/internal/util-cache/src/main/scala/sbt/internal/util/Output.scala
+++ b/util-cache/src/main/scala/sbt/util/Output.scala
@@ -1,4 +1,4 @@
-package sbt.internal.util
+package sbt.util
 
 import java.io.{ Closeable, OutputStream }
 import sjsonnew.{ IsoString, JsonWriter, SupportConverter }
diff --git a/internal/util-cache/src/main/scala/sbt/internal/util/SeparatedCache.scala b/util-cache/src/main/scala/sbt/util/SeparatedCache.scala
similarity index 98%
rename from internal/util-cache/src/main/scala/sbt/internal/util/SeparatedCache.scala
rename to util-cache/src/main/scala/sbt/util/SeparatedCache.scala
index be8f11a38..c8772e034 100644
--- a/internal/util-cache/src/main/scala/sbt/internal/util/SeparatedCache.scala
+++ b/util-cache/src/main/scala/sbt/util/SeparatedCache.scala
@@ -1,7 +1,7 @@
 /* sbt -- Simple Build Tool
  * Copyright 2009 Mark Harrah
  */
-package sbt.internal.util
+package sbt.util
 
 import scala.util.Try
 
diff --git a/internal/util-cache/src/main/scala/sbt/internal/util/StampedFormat.scala b/util-cache/src/main/scala/sbt/util/StampedFormat.scala
similarity index 98%
rename from internal/util-cache/src/main/scala/sbt/internal/util/StampedFormat.scala
rename to util-cache/src/main/scala/sbt/util/StampedFormat.scala
index 213f50ec5..c78186d1c 100644
--- a/internal/util-cache/src/main/scala/sbt/internal/util/StampedFormat.scala
+++ b/util-cache/src/main/scala/sbt/util/StampedFormat.scala
@@ -1,4 +1,4 @@
-package sbt.internal.util
+package sbt.util
 
 import scala.reflect.Manifest
 
diff --git a/internal/util-cache/src/test/scala/CacheSpec.scala b/util-cache/src/test/scala/CacheSpec.scala
similarity index 97%
rename from internal/util-cache/src/test/scala/CacheSpec.scala
rename to util-cache/src/test/scala/CacheSpec.scala
index a3b0dd5e1..109fd1247 100644
--- a/internal/util-cache/src/test/scala/CacheSpec.scala
+++ b/util-cache/src/test/scala/CacheSpec.scala
@@ -1,4 +1,4 @@
-package sbt.internal.util
+package sbt.util
 
 import sbt.io.IO
 import sbt.io.syntax._
@@ -9,6 +9,7 @@ import sjsonnew.IsoString
 import sjsonnew.support.scalajson.unsafe.{ CompactPrinter, Converter, Parser }
 
 import scala.json.ast.unsafe.JValue
+import sbt.internal.util.UnitSpec
 
 class CacheSpec extends UnitSpec {
 
diff --git a/internal/util-cache/src/test/scala/FileInfoSpec.scala b/util-cache/src/test/scala/FileInfoSpec.scala
similarity index 93%
rename from internal/util-cache/src/test/scala/FileInfoSpec.scala
rename to util-cache/src/test/scala/FileInfoSpec.scala
index ed7b4ec28..cae8e15b1 100644
--- a/internal/util-cache/src/test/scala/FileInfoSpec.scala
+++ b/util-cache/src/test/scala/FileInfoSpec.scala
@@ -1,7 +1,8 @@
-package sbt.internal.util
+package sbt.util
 
 import scala.json.ast.unsafe._
 import sjsonnew._, support.scalajson.unsafe._
+import sbt.internal.util.UnitSpec
 
 class FileInfoSpec extends UnitSpec {
   val file = new java.io.File(".").getAbsoluteFile
diff --git a/internal/util-cache/src/test/scala/HListFormatSpec.scala b/util-cache/src/test/scala/HListFormatSpec.scala
similarity index 93%
rename from internal/util-cache/src/test/scala/HListFormatSpec.scala
rename to util-cache/src/test/scala/HListFormatSpec.scala
index 23e4cde0f..e2d5d38fa 100644
--- a/internal/util-cache/src/test/scala/HListFormatSpec.scala
+++ b/util-cache/src/test/scala/HListFormatSpec.scala
@@ -1,8 +1,9 @@
-package sbt.internal.util
+package sbt.util
 
 import scala.json.ast.unsafe._
 import sjsonnew._, support.scalajson.unsafe._
 import CacheImplicits._
+import sbt.internal.util.{ UnitSpec, HNil }
 
 class HListFormatSpec extends UnitSpec {
   val quux = 23 :+: "quux" :+: true :+: HNil
diff --git a/internal/util-cache/src/test/scala/SingletonCacheSpec.scala b/util-cache/src/test/scala/SingletonCacheSpec.scala
similarity index 98%
rename from internal/util-cache/src/test/scala/SingletonCacheSpec.scala
rename to util-cache/src/test/scala/SingletonCacheSpec.scala
index da883d446..5956746de 100644
--- a/internal/util-cache/src/test/scala/SingletonCacheSpec.scala
+++ b/util-cache/src/test/scala/SingletonCacheSpec.scala
@@ -1,4 +1,4 @@
-package sbt.internal.util
+package sbt.util
 
 import sbt.io.IO
 import sbt.io.syntax._
@@ -9,6 +9,7 @@ import sjsonnew.{ Builder, deserializationError, IsoString, JsonFormat, Unbuilde
 import sjsonnew.support.scalajson.unsafe.{ CompactPrinter, Converter, Parser }
 
 import scala.json.ast.unsafe.JValue
+import sbt.internal.util.UnitSpec
 
 class SingletonCacheSpec extends UnitSpec {
 
diff --git a/internal/util-tracking/NOTICE b/util-tracking/NOTICE
similarity index 100%
rename from internal/util-tracking/NOTICE
rename to util-tracking/NOTICE
diff --git a/internal/util-tracking/src/main/scala/sbt/internal/util/ChangeReport.scala b/util-tracking/src/main/scala/sbt/util/ChangeReport.scala
similarity index 99%
rename from internal/util-tracking/src/main/scala/sbt/internal/util/ChangeReport.scala
rename to util-tracking/src/main/scala/sbt/util/ChangeReport.scala
index 801fc22cf..af8154729 100644
--- a/internal/util-tracking/src/main/scala/sbt/internal/util/ChangeReport.scala
+++ b/util-tracking/src/main/scala/sbt/util/ChangeReport.scala
@@ -1,7 +1,7 @@
 /* sbt -- Simple Build Tool
  * Copyright 2009, 2010 Mark Harrah
  */
-package sbt.internal.util
+package sbt.util
 
 object ChangeReport {
   def modified[T](files: Set[T]): ChangeReport[T] =
diff --git a/util-tracking/src/main/scala/sbt/util/FileFunction.scala b/util-tracking/src/main/scala/sbt/util/FileFunction.scala
new file mode 100644
index 000000000..cdc1cc4e8
--- /dev/null
+++ b/util-tracking/src/main/scala/sbt/util/FileFunction.scala
@@ -0,0 +1,143 @@
+package sbt.util
+
+import java.io.File
+
+object FileFunction {
+  type UpdateFunction = (ChangeReport[File], ChangeReport[File]) => Set[File]
+  private val defaultInStyle = FileInfo.lastModified
+  private val defaultOutStyle = FileInfo.exists
+
+  /**
+   * Generic change-detection helper used to help build / artifact generation /
+   * etc. steps detect whether or not they need to run. Returns a function whose
+   * input is a Set of input files, and subsequently executes the action function
+   * (which does the actual work: compiles, generates resources, etc.), returning
+   * a Set of output files that it generated.
+   *
+   * The input file and resulting output file state is cached in stores issued by
+   * `storeFactory`. On each invocation, the state of the input and output
+   * files from the previous run is compared against the cache, as is the set of
+   * input files. If a change in file state / input files set is detected, the
+   * action function is re-executed.
+   *
+   * @param cacheBaseDirectory The folder in which to store
+   * @param action The work function, which receives a list of input files and returns a list of output files
+   */
+  def cached(cacheBaseDirectory: File)(action: Set[File] => Set[File]): Set[File] => Set[File] =
+    cached(cacheBaseDirectory, inStyle = defaultInStyle, outStyle = defaultOutStyle)(action)
+
+  /**
+   * Generic change-detection helper used to help build / artifact generation /
+   * etc. steps detect whether or not they need to run. Returns a function whose
+   * input is a Set of input files, and subsequently executes the action function
+   * (which does the actual work: compiles, generates resources, etc.), returning
+   * a Set of output files that it generated.
+   *
+   * The input file and resulting output file state is cached in stores issued by
+   * `storeFactory`. On each invocation, the state of the input and output
+   * files from the previous run is compared against the cache, as is the set of
+   * input files. If a change in file state / input files set is detected, the
+   * action function is re-executed.
+   *
+   * @param cacheBaseDirectory The folder in which to store
+   * @param inStyle The strategy by which to detect state change in the input files from the previous run
+   * @param action The work function, which receives a list of input files and returns a list of output files
+   */
+  def cached(cacheBaseDirectory: File, inStyle: FileInfo.Style)(action: Set[File] => Set[File]): Set[File] => Set[File] =
+    cached(cacheBaseDirectory, inStyle = inStyle, outStyle = defaultOutStyle)(action)
+
+  /**
+   * Generic change-detection helper used to help build / artifact generation /
+   * etc. steps detect whether or not they need to run. Returns a function whose
+   * input is a Set of input files, and subsequently executes the action function
+   * (which does the actual work: compiles, generates resources, etc.), returning
+   * a Set of output files that it generated.
+   *
+   * The input file and resulting output file state is cached in stores issued by
+   * `storeFactory`. On each invocation, the state of the input and output
+   * files from the previous run is compared against the cache, as is the set of
+   * input files. If a change in file state / input files set is detected, the
+   * action function is re-executed.
+   *
+   * @param cacheBaseDirectory The folder in which to store
+   * @param inStyle The strategy by which to detect state change in the input files from the previous run
+   * @param outStyle The strategy by which to detect state change in the output files from the previous run
+   * @param action The work function, which receives a list of input files and returns a list of output files
+   */
+  def cached(cacheBaseDirectory: File, inStyle: FileInfo.Style, outStyle: FileInfo.Style)(action: Set[File] => Set[File]): Set[File] => Set[File] =
+    cached(CacheStoreFactory(cacheBaseDirectory), inStyle, outStyle)((in, out) => action(in.checked))
+
+  /**
+   * Generic change-detection helper used to help build / artifact generation /
+   * etc. steps detect whether or not they need to run. Returns a function whose
+   * input is a Set of input files, and subsequently executes the action function
+   * (which does the actual work: compiles, generates resources, etc.), returning
+   * a Set of output files that it generated.
+   *
+   * The input file and resulting output file state is cached in stores issued by
+   * `storeFactory`. On each invocation, the state of the input and output
+   * files from the previous run is compared against the cache, as is the set of
+   * input files. If a change in file state / input files set is detected, the
+   * action function is re-executed.
+   *
+   * @param storeFactory The factory to use to get stores for the input and output files.
+   * @param action The work function, which receives a list of input files and returns a list of output files
+   */
+  def cached(storeFactory: CacheStoreFactory)(action: UpdateFunction): Set[File] => Set[File] =
+    cached(storeFactory, inStyle = defaultInStyle, outStyle = defaultOutStyle)(action)
+
+  /**
+   * Generic change-detection helper used to help build / artifact generation /
+   * etc. steps detect whether or not they need to run. Returns a function whose
+   * input is a Set of input files, and subsequently executes the action function
+   * (which does the actual work: compiles, generates resources, etc.), returning
+   * a Set of output files that it generated.
+   *
+   * The input file and resulting output file state is cached in stores issued by
+   * `storeFactory`. On each invocation, the state of the input and output
+   * files from the previous run is compared against the cache, as is the set of
+   * input files. If a change in file state / input files set is detected, the
+   * action function is re-executed.
+   *
+   * @param storeFactory The factory to use to get stores for the input and output files.
+   * @param inStyle The strategy by which to detect state change in the input files from the previous run
+   * @param action The work function, which receives a list of input files and returns a list of output files
+   */
+  def cached(storeFactory: CacheStoreFactory, inStyle: FileInfo.Style)(action: UpdateFunction): Set[File] => Set[File] =
+    cached(storeFactory, inStyle = inStyle, outStyle = defaultOutStyle)(action)
+
+  /**
+   * Generic change-detection helper used to help build / artifact generation /
+   * etc. steps detect whether or not they need to run. Returns a function whose
+   * input is a Set of input files, and subsequently executes the action function
+   * (which does the actual work: compiles, generates resources, etc.), returning
+   * a Set of output files that it generated.
+   *
+   * The input file and resulting output file state is cached in stores issued by
+   * `storeFactory`. On each invocation, the state of the input and output
+   * files from the previous run is compared against the cache, as is the set of
+   * input files. If a change in file state / input files set is detected, the
+   * action function is re-executed.
+   *
+   * @param storeFactory The factory to use to get stores for the input and output files.
+   * @param inStyle The strategy by which to detect state change in the input files from the previous run
+   * @param outStyle The strategy by which to detect state change in the output files from the previous run
+   * @param action The work function, which receives a list of input files and returns a list of output files
+   */
+  def cached(storeFactory: CacheStoreFactory, inStyle: FileInfo.Style, outStyle: FileInfo.Style)(action: UpdateFunction): Set[File] => Set[File] =
+    {
+      lazy val inCache = Difference.inputs(storeFactory.make("in-cache"), inStyle)
+      lazy val outCache = Difference.outputs(storeFactory.make("out-cache"), outStyle)
+      inputs =>
+        {
+          inCache(inputs) { inReport =>
+            outCache { outReport =>
+              if (inReport.modified.isEmpty && outReport.modified.isEmpty)
+                outReport.checked
+              else
+                action(inReport, outReport)
+            }
+          }
+        }
+    }
+}
diff --git a/internal/util-tracking/src/main/scala/sbt/internal/util/Tracked.scala b/util-tracking/src/main/scala/sbt/util/Tracked.scala
similarity index 72%
rename from internal/util-tracking/src/main/scala/sbt/internal/util/Tracked.scala
rename to util-tracking/src/main/scala/sbt/util/Tracked.scala
index 4db2acc0c..dcd5658e9 100644
--- a/internal/util-tracking/src/main/scala/sbt/internal/util/Tracked.scala
+++ b/util-tracking/src/main/scala/sbt/util/Tracked.scala
@@ -1,7 +1,7 @@
 /* sbt -- Simple Build Tool
  * Copyright 2009, 2010 Mark Harrah
  */
-package sbt.internal.util
+package sbt.util
 
 import scala.util.{ Failure, Try, Success }
 
@@ -15,22 +15,48 @@ object Tracked {
 
   import CacheImplicits.LongJsonFormat
 
+  /**
+   * Creates a tracker that provides the last time it was evaluated.
+   * If the function throws an exception.
+   */
+  def tstamp(store: CacheStore): Timestamp = tstamp(store, true)
+
+  /**
+   * Creates a tracker that provides the last time it was evaluated.
+   * If the function throws an exception.
+   */
+  def tstamp(cacheFile: File): Timestamp = tstamp(CacheStore(cacheFile))
+
   /**
    * Creates a tracker that provides the last time it was evaluated.
    * If 'useStartTime' is true, the recorded time is the start of the evaluated function.
    * If 'useStartTime' is false, the recorded time is when the evaluated function completes.
    * In both cases, the timestamp is not updated if the function throws an exception.
    */
-  def tstamp(store: CacheStore, useStartTime: Boolean = true): Timestamp = new Timestamp(store, useStartTime)
+  def tstamp(store: CacheStore, useStartTime: Boolean): Timestamp = new Timestamp(store, useStartTime)
+
+  /**
+   * Creates a tracker that provides the last time it was evaluated.
+   * If 'useStartTime' is true, the recorded time is the start of the evaluated function.
+   * If 'useStartTime' is false, the recorded time is when the evaluated function completes.
+   * In both cases, the timestamp is not updated if the function throws an exception.
+   */
+  def tstamp(cacheFile: File, useStartTime: Boolean): Timestamp = tstamp(CacheStore(cacheFile), useStartTime)
 
   /** Creates a tracker that provides the difference between a set of input files for successive invocations.*/
   def diffInputs(store: CacheStore, style: FileInfo.Style): Difference =
     Difference.inputs(store, style)
 
+  /** Creates a tracker that provides the difference between a set of input files for successive invocations.*/
+  def diffInputs(cacheFile: File, style: FileInfo.Style): Difference = diffInputs(CacheStore(cacheFile), style)
+
   /** Creates a tracker that provides the difference between a set of output files for successive invocations.*/
   def diffOutputs(store: CacheStore, style: FileInfo.Style): Difference =
     Difference.outputs(store, style)
 
+  /** Creates a tracker that provides the difference between a set of output files for successive invocations.*/
+  def diffOutputs(cacheFile: File, style: FileInfo.Style): Difference = diffOutputs(CacheStore(cacheFile), style)
+
   /** Creates a tracker that provides the output of the most recent invocation of the function */
   def lastOutput[I, O: JsonFormat](store: CacheStore)(f: (I, Option[O]) => O): I => O = { in =>
     val previous = Try { store.read[O] }.toOption
@@ -39,6 +65,10 @@ object Tracked {
     next
   }
 
+  /** Creates a tracker that provides the output of the most recent invocation of the function */
+  def lastOutput[I, O: JsonFormat](cacheFile: File)(f: (I, Option[O]) => O): I => O =
+    lastOutput(CacheStore(cacheFile))(f)
+
   /**
    * Creates a tracker that indicates whether the arguments given to f have changed since the most
    * recent invocation.
@@ -53,6 +83,13 @@ object Tracked {
     result
   }
 
+  /**
+   * Creates a tracker that indicates whether the arguments given to f have changed since the most
+   * recent invocation.
+   */
+  def inputChanged[I: JsonFormat: SingletonCache, O](cacheFile: File)(f: (Boolean, I) => O): I => O =
+    inputChanged(CacheStore(cacheFile))(f)
+
   private final class CacheHelp[I: JsonFormat](val sc: SingletonCache[I]) {
     def save(store: CacheStore, value: I): Unit = {
       store.write(value)
@@ -169,45 +206,3 @@ class Difference(val store: CacheStore, val style: FileInfo.Style, val defineCle
       result
     }
 }
-
-object FileFunction {
-  type UpdateFunction = (ChangeReport[File], ChangeReport[File]) => Set[File]
-
-  /**
-   * Generic change-detection helper used to help build / artifact generation /
-   * etc. steps detect whether or not they need to run. Returns a function whose
-   * input is a Set of input files, and subsequently executes the action function
-   * (which does the actual work: compiles, generates resources, etc.), returning
-   * a Set of output files that it generated.
-   *
-   * The input file and resulting output file state is cached in stores issued by
-   * `storeFactory`. On each invocation, the state of the input and output
-   * files from the previous run is compared against the cache, as is the set of
-   * input files. If a change in file state / input files set is detected, the
-   * action function is re-executed.
-   *
-   * @param storeFactory The factory to use to get stores for the input and output files.
-   * @param inStyle The strategy by which to detect state change in the input files from the previous run
-   * @param outStyle The strategy by which to detect state change in the output files from the previous run
-   * @param action The work function, which receives a list of input files and returns a list of output files
-   */
-  def cached(storeFactory: CacheStoreFactory, inStyle: FileInfo.Style = FileInfo.lastModified, outStyle: FileInfo.Style = FileInfo.exists)(action: Set[File] => Set[File]): Set[File] => Set[File] =
-    cached(storeFactory)(inStyle, outStyle)((in, out) => action(in.checked))
-
-  def cached(storeFactory: CacheStoreFactory)(inStyle: FileInfo.Style, outStyle: FileInfo.Style)(action: UpdateFunction): Set[File] => Set[File] =
-    {
-      lazy val inCache = Difference.inputs(storeFactory.derive("in-cache"), inStyle)
-      lazy val outCache = Difference.outputs(storeFactory.derive("out-cache"), outStyle)
-      inputs =>
-        {
-          inCache(inputs) { inReport =>
-            outCache { outReport =>
-              if (inReport.modified.isEmpty && outReport.modified.isEmpty)
-                outReport.checked
-              else
-                action(inReport, outReport)
-            }
-          }
-        }
-    }
-}
diff --git a/internal/util-tracking/src/test/scala/sbt/internal/util/TrackedSpec.scala b/util-tracking/src/test/scala/sbt/util/TrackedSpec.scala
similarity index 90%
rename from internal/util-tracking/src/test/scala/sbt/internal/util/TrackedSpec.scala
rename to util-tracking/src/test/scala/sbt/util/TrackedSpec.scala
index df23ae8e7..90513cad6 100644
--- a/internal/util-tracking/src/test/scala/sbt/internal/util/TrackedSpec.scala
+++ b/util-tracking/src/test/scala/sbt/util/TrackedSpec.scala
@@ -1,4 +1,4 @@
-package sbt.internal.util
+package sbt.util
 
 import sbt.io.IO
 import sbt.io.syntax._
@@ -6,14 +6,9 @@ import sbt.io.syntax._
 import CacheImplicits._
 
 import sjsonnew.IsoString
-import sjsonnew.support.scalajson.unsafe.{ CompactPrinter, Converter, Parser }
-
-import scala.json.ast.unsafe.JValue
+import sbt.internal.util.UnitSpec
 
 class TrackedSpec extends UnitSpec {
-
-  implicit val isoString: IsoString[JValue] = IsoString.iso(CompactPrinter.apply, Parser.parseUnsafe)
-
   "lastOutput" should "store the last output" in {
     withStore { store =>
 
@@ -133,7 +128,7 @@ class TrackedSpec extends UnitSpec {
 
   private def withStore(f: CacheStore => Unit): Unit =
     IO.withTemporaryDirectory { tmp =>
-      val store = new FileBasedStore(tmp / "cache-store", Converter)
+      val store = CacheStore(tmp / "cache-store")
       f(store)
     }