I have read the replies to this message, and have unfortunately found it doesn't seem to answer my questions [I have been handed back and forth a bit between the MINGW32 help people and here, apparently the place for GCJ Help] I wish to install the GCJ version 4.6.0 on MINGW32: I wish to compile it from source. I have read the documentation, and don't find it useful for my situation. I am running the MinGW32 environment, which has gcc already installed as part of it's default MSYS 1.0 installation. I ask the following: -How do I $> ./configure;make;install; GCJ 4.6 with success under mingw32? -Does the GCJ 4.6.0 allow java code to be compiled into Linux/Mac/Windows executables, ie machine code for those operating systems? -Even failing my verey first question, for a small Test.java program, could I be given an example gcj command line for a platform specific binary compilation? -Is 4.6.0 considered stable, and does it support new things in Java like Generics/autoboxing-unboxing/annotations/Enums? -Does it work of a PATH/CLASSPATH variable?