ZipStar is a free archiving application for home users. It can create, modify and extract the archive formats SQX, CAB and ZIP. Besides the application itself, ZipStar also provides an extension for the Windows Explorer. With this extension it is possible to extract or create archives directly within Windows Explorer.

ZipStar may be used free of charge if you

• are a student, teacher or some other kind of member of a teaching facility (public/private school or university);
• use the software exclusively for private and non-profit purposes.

http://www.speedproject.de/enu/zipstar/index.html