tarmill compresses and encrypts tar archives, and is designed for use in backup scripts. Unlike most other solutions, each archive member is handled separately, so damage in the middle of the archive does not render the rest of the archive unusable; it is possible to resume at the next readable member header. Compressed and encrypted archives remain valid tar files, so any well-behaved tar implementation will be able to list (but not extract) them.
UCL is a portable lossless data compression library written in ANSI C. Both the source code and the compressed data format are designed to be portable across platforms. UCL supports in-place decompression. It implements a number of compression algorithms that achieve an excellent compression ratio while allowing very fast decompression. Decompression requires no additional memory.
The True Audio (TTA) codec is a simple realtime lossless audio compressor. It performs lossless compression on multichannel 8, 16, and 24 bit data of Wav audio files. The compression ratios depend on the type of music file being compressed, but the compression size will generally range between 30%-70% of the original. TTA supports both ID3v1 and ID3v2 information tags.