A set of (Perl) scripts that allows you to optimize backups to S3 by packing files/dirs into a minimal set of archives that are likely to remain stable between backups, even if the underlying files change, thus minimizing the number S3 items.
GNet Server - Network compression client/server software. Compresses data over slow networks to save on the cost of bandwidth. Server is developed for Unix and Windows platforms, The client will run on Windows based PCs.
PHP Unarchiver is Un-Archiver tool that works with Tarballs, Zips and Rars. Unarchiver is a browser-based archive management tool for users who do not have direct access to their servers.