A feature in Visual Studio Team Studio that was immediately appealing to me was shelving. The goal of this tool is replicate that general functionality in Perforce.
Project homepage:
http://code.google.com/p/p4shelf/
Programming language(s): C#,C++,Python
License: gpl2
Some source files from: p4shelf/IronPython/Src/IronPython/bin
Debug/
IronMath.dll
IronPython.dll
See more files for this project here