... RCMP TSSIT OPS-II 7 Passes, and Peter Gutmann 35 Passes.
The program is written in C# .NET. The source code is also available for download and you may contribute to the development here.
If you want a clear explanation on how each of the algorithms work, please refer here: http://www.phoebekwok.com/publications/GJY_SecureDataShredder.pdf