packARC is a “media archiver” uniting my packJPG, packMP3, packPNM and packARI compression algorithms under one hood. Although it will compress any file you throw at it, it will perform best for MP3 and JPEG and it will perform well with PNM and BMP. For other file types it highly depends on their content, in the worst cases packARC may even be outperformed by classic ZIP.

Download it from here:
packARC v0.7RC17 (LGPL)

packARC includes it’s own source code (that includes packMP3, packJPG, packARI and packPNM source codes) and is completely open source under the LGPL.

At the moment, packARC is still in beta stage. There are no known bugs when running under Microsoft Windows, but earlier versions had some trouble when compiling and running under Linux. This should be fixed now, but testing is still needed. Any help assuring my fix works is greatly appreciated. See also the packARC v0.7 thread on encode.su.