crunch/crnlib is a lossy texture compression tool and library for developers that distributes and uses content in the DXT1/5/N or 3DC/BC5 compressed mipmapped texture formats. crnlib can compress mipmapped 2D textures and cubemaps to .8-1.25 bits/texel, and normal maps to 1.75-2 bits/texel. crnlib's quality and performance is competitive to transform-based solutions, or other offline/real-time DXTn compressors such as squish or ATI_Compress. crnlib implements a new form of "clustered" DXTn compression, with a compressed texture data format that was carefully designed to be very quickly transcodable directly to raw DXTn texture bits with no intermediate recompression step or individual pixel-level operations. The typical single threaded transcode to DXTn rate is equivalent to 100-250 megatexels/sec. Fast random access to individual mipmap levels is supported.
Lhasa is a Free Software replacement for the Unix LHA tool, for decompressing .lzh (LHA/LHarc) and .lzs (LArc) archives. The backend for the tool is a library, so it can be reused for other purposes. Lhasa aims to be compatible with as many types of lzh/lzs archives as possible. It also aims to generate the same output as the (non-free) Unix LHA tool, so it will act as a drop-in free replacement.
iZip provides an easy way to manage .ZIP, .ZIPX, and .RAR archives on Mac systems. When you open an archive with iZip, it appears as a removable disk. This allows management of your files right inside the OS X Finder. All view modes (including cover-flow) just work. For extra security, iZip supports up to 256 bit AES zip encryption.
snappy-c is a C port of the google snappy compressor (http://code.google.com/p/snappy/). The compressor is very fast with a reasonable compression ratio. It is mainly useful for projects that cannot integrate C++ code, but want snappy. It also contains a command line tool, a benchmark, random test code, and a fuzz tester. The compression code supports scather-gather and linear buffers. The scather gather code is ifdefed (-DSG) and can be removed with unifdef.
Fivebit is a Python 3 compression library for short text strings. It compresses short strings of text into five bit encoding, which yields a 37.5% reduction for lowercase ASCII. There is also a dictionary for the 1024 most common English words (3 letters or longer). Punctuation, digits, and normal symbols will usually take up 10 bits each, and oddball Unicode characters will take up more space again.