
Each night shell scripts on the server build up nightly versions of all active projects. These are packaged into three kinds of packages, a JAR file, a source JAR file and a zipped up javadoc file. All of these can be downloaded from here:
Nightly Builds
There are also stable builds which are nighly builds that are deemed stable. They may have the same naming convention but are only changed when there is a major feature change or the code has been used long enough to be deemed stable. They can be found here:
Stable Builds