To see the differences between the release versions, see the release notes. If you intend to do any benchmarking, please read the Benchmarking Guidelines. The downloads are for Win32 only. Available releases:

Binaries (Win32)

The software is free, and open source, under a BSD-style license. Sun's license is included in the download, however, if you'd like to look at it first, it is here:

Source Code

The source code repository (under Subversion) can be found at:

Pre-packaged Source

Current source can be obtained from the source repository above. The below files conveniently package the source at various important points.