its open source and beats the hell out of the consistently nagging winrar...
Over 150 file types supported
Open, test and extract over 150 archive types: ACE, ARJ, CAB, DMG, ISO, LHA, RAR, UDF, ZIPX files and more file formats...
Create and convert 7Z, ARC, BZ2, GZ, *PAQ, PEA, QUAD/BALZ, TAR, UPX, WIM, XZ, and ZIP files.
Free WinRar WinZip alternative
Easy to use GUI with Drag&Drop and context menu integration. High speed, compression ratio, stability and security, relying on proven Open Source technologies from 7-Zip, FreeArc, PAQ, UPX and other state of art projects.