CJam is a stack-oriented programming language heavily inspired from GolfScript and suitable for code golfing.
It is an interpreted language, and the official interpreter is written in java.
The name stands for cherry jam. The author also plans to use the language in Google Code Jam competitions, but otherwise it is not related to the Code Jam or Google in any way.
In order to run a CJam program, download the latest jar file, e.g. cjam-0.6.2.jar, and run this command:
java -jar cjam-0.6.2.jar file.cjam
You can also launch an interactive shell:
java -cp cjam-0.6.2.jar net.aditsu.cjam.Shell
New: browser-based interpreter at http://cjam.aditsu.net