EditSharpZipLib Compression Library
SharpZipLib is a .NET compression library that supports Zip files using both stored and deflate compression methods, PKZIP 2.0 style encryption, tar with GNU long filename extensions, gzip, zlib and raw deflate, as well as BZip2.
Zip64 is supported while Deflate64 is not yet supported.
It can be compiled for the compact framework as well as the full range of desktop CLR's.