#ziplib (pronounced SharpZipLib) is a free, open-source compression library for the .NET Framework. Data can be handled using the following formats:

· Zip: This format archives multiple files into one file and compresses the results. Uses the deflate algorithm.
· Gzip: This format is often used in Unix and GNU Linux. It does not archive multiple files, so it is frequently used in conjunction with the ‘tar’ command. Also uses the deflate algorithm.
· Tar (“Tape archive”): Archives a set of files and directories into one file. It does not compress the files. Often used in conjunction with gzip to compress.
· Bzip2: This uses the same file format as gzip, but a different compression algorithm, called BWT. Produces better compression than gzip, but is much slower.

SharpZipLib also computes checksums. Ported to .NET from the GNU Classpath ZIP library for Java, the developer, ic#code, wrote the library entirely in C#. Because it is a strong-named assembly, it can be shared with other applications or used in other projects when registered in the Global Assembly Cache (GAC).

The library currently lacks Zip file splitting/spanning, can’t create custom self-extracting Zip files, and can’t read or write files to memory.

The project for the library included in the download is intended to be opened in ic#code’s own IDE, #develop (SharpDevelop), which, although a work in progress, gives programmers a free Windows Forms designer similar to VS.NET, for C# and VB.NET. The library and its source code are distributed under the GNU General Public License, with an exception.