DotNetZip Library

In my quest for application development using as many free and open source libraries as possible (due largely to the small audience of my mineral collecting software...)

DotNetZip Library - DotNetZip is an easy-to-use, FAST, FREE class library and toolset for manipulating zip files or folders. Zip and Unzip is easy: with DotNetZip, .NET applications written in VB, C# - any .NET language - can easily create, read, extract, or update zip files. For Mono or MS .NET.