storeBackup is a backup utility that stores files on other disks. It's able to compress data, and recognize copying and moving of files and directories (deduplication), and unifies the advantages of traditional full and incremental backups. It can handle big image files with block-wise changes efficiently. Depending on its contents, every file is stored only once on disk. Tools for analyzing backup data and restoring are provided. Once archived, files are accessible by mounting file systems (locally, or via Samba or NFS). It is easy to install and configure. Additional features are backup consistency checking, offline backups, and replication of backups.
pngcrush is an excellent batch-mode compression utility for PNG images. Depending on the application that created the original PNGs, it can improve the file size anywhere from a few percent to 40% or more (completely losslessly). The utility also allows specified PNG chunks (e.g. text comments) to be inserted or deleted, and it can fix incorrect gamma info written by Photoshop 5.0 as well as the erroneous iCCP chunk written by Photoshop 5.5.
OzVM (Virtual Machine Project) is a simple, lightweight, secure virtual machine. The current target application of OzVM is OzStream, which allows platform independent self-decoding of data. The vision of OzStream is to make any and all compressed media self-extracting. OzStream abstracts compressed media from client applications, providing new freedom for users, developers, and compression techniques.
Star is a very fast, POSIX-compliant tar archiver, maintained for more than 30 years. It saves many files together into a single tape or disk archive, and can restore individual files from the archive. It includes command line interfaces for the "tar", "Sun-Tar", "cpio", "pax", and "gnutar" command-line syntax. It includes a FIFO for speed, a pattern matcher, multi-volume support, the ability to archive sparse files and ACLs, the ability to archive extended file flags, automatic archive format detection, automatic byte order recognition, automatic archive compression/decompression, remote archives, and special features that allow star to be used for full and incremental backups. It includes the only known platform independent "rmt" server program.
Shoelacer attempts to generate a pair of small C functions that compress or decompress a set of data (primarily short strings) presented to it, and possibly other data of that kind. The data it is given may consist of entries of just a few bytes or longer. Its goal is to be reasonably fast with a tiny memory overhead. Compression performance is not so much the goal, although it certainly isn't ignored.