Note that there may be problems with newer versions of Java. See Section 1.3 for instructions on filing bug reports.
The sections below contain platform-specific notes.
Linux Java installations usually have $JAVA_HOME already set correctly via a /etc/profile.d script.
Cygwin is unique among the platforms in that it doesn't have a native Java package, and has to use the one from Windows. One consequence of that is that Java programs won't understand Cygwin paths, and conversion to Windows paths has to be made. Relative paths usually work best on Cygwin.
When both a script and an executable with the same name are present, Cygwin will prefer the executable. This allows the use of the Windows executables, xjc.exe and xj.exe on Cygwin, but also means that $CLASSPATH, $JAVA_HOME, etc., need to be set in the Windows format (with drive letters and `;' as the separator, for a looser integration with the rest of the tools).
It is not possible to achieve full integration, as XJ programs will still require data file names and other parameters passed via the command line, properties, or config files as Windows paths. The regression test scripts are patched to work around this issue, but again, it is best to use relative paths with XJ on Cygwin.
Note also that, as in any Unix shell, if backslashes are used on the command line in Cygwin, they need to be either doubled, or properly quoted using single quotes (`''). To avoid the need for quoting, forward slashes (`/') can also be used for Windows style paths.
The regression test framework requires Cygwin to run under Windows, and will not work in a pure Windows environment.
XJ should work on Mac OS X. However, it hasn't been extensively tested on this platform.