Determining the Build Number

The easiest way to know which build number you are using is to execute your game. The build number is displayed on the log at startup. If this isn't possible or you've turned logging off you can find a file named "version" at the top level of the JAR file. This file contains a single property of the format:

#Tue Dec 05 15:59:28 PST 2006 build=XXX

Where XXX is the build number of the JAR that you have.

Current Valid Extension Versions

A list of current version tags and their respective build dates can be found here