Improvements to sbt.bat suggested by @retronym

project/packaging.scala

@@ -173,6 +173,7 @@ object Packaging {
       <Package Description='Simple Build Tool launcher script.'
                 Comments='First attempt to create an SBT windows installer, bear with me.'
                 Manufacturer='Typesafe, Inc.' 
+                InstallScope='perMachine'
                 InstallerVersion='200' 
                 Compressed='yes' />
  

src/windows/sbt.bat

@@ -1,3 +1,42 @@
+@REM SBT launcher script
+@REM 
+@REM Envioronment:
+@REM JAVA_HOME - location of a JDK home dir (mandatory)
+@REM SBT_OPTS  - JVM options (optional)
+
+
+@setlocal
+
 @echo off
 set SBT_HOME=%~dp0
-java -Xmx512M -Dsbt.log.format=true -cp "%SBT_HOME%jansi.jar;%SBT_HOME%sbt-launch.jar;%SBT_HOME%classes" SbtJansiLaunch %*
+set ERROR_CODE=0
+
+rem We use the value of the JAVACMD environment variable if defined
+set _JAVACMD=%JAVACMD%
+
+if "%_JAVACMD%"=="" (
+  if not "%JAVA_HOME%"=="" (
+    if exist "%JAVA_HOME%\bin\java.exe" set "_JAVACMD=%JAVA_HOME%\bin\java.exe"
+  )
+)
+
+if "%_JAVACMD%"=="" set _JAVACMD=java
+
+rem We use the value of the JAVA_OPTS environment variable if defined
+set _JAVA_OPTS=%JAVA_OPTS%
+if "%_JAVA_OPTS%"=="" set _JAVA_OPTS=-Xmx512M -XX:MaxPermSize=256m -XX:ReservedCodeCacheSize=128m -Dsbt.log.format=true
+
+:run
+
+"%_JAVACMD%" %_JAVA_OPTS% %SBT_OPTS% -cp "%SBT_HOME%jansi.jar;%SBT_HOME%sbt-launch.jar;%SBT_HOME%classes" SbtJansiLaunch %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+
+@endlocal
+
+exit /B %ERROR_CODE%