The RAZip bitstream format was designed to provide a faster random access to compressed data than what is currently possible using the GZIP format. Its major features include fast random access to compressed data, freedom from patents, single-pass coding/decoding using a bounded amount of intermediate storage, the ability to choose from one of many algorithms for compression, encryption, or error correction, and comprehensive support for Unix file metadata, Macintosh file metadata, and arbitrary file metadata.
The lzlib compression library provides in-memory LZMA compression and decompression functions, including integrity checking of the decompressed data. The compressed data format used by the library is the lzip format. The lzip file format is designed for long-term data archiving. It is clean, provides very safe 4-factor integrity checking, and is backed by the recovery capabilities of lziprecover.
zlib is designed to be a free, general-purpose, legally unencumbered, lossless data-compression library for use on virtually any computer hardware and operating system. The zlib data format is itself portable across platforms. Unlike the LZW compression method used in Unix compress(1), the compression method currently used in zlib essentially never expands the data. (LZW can double or triple the file size in extreme cases.) zlib's memory footprint is also independent of the input data and can be reduced, if necessary, at some cost in compression.
LZO is a portable lossless data compression library written in ANSI C. It offers pretty fast compression and very fast decompression. Decompression requires no memory. In addition there are slower compression levels achieving a quite competitive compression ratio while still decompressing at this very high speed.
pkt is a universal XML packet archiver. It can manipulate files for backing up documents, transferring them across networks, emailing them, and sharing them by other means (p2p etc). It uses plugin filters to do the job and handles virtually any format available if there is a plugin for it. It handles encryption, compression, conversion, parity checking, decryption, decoding, repairing, rebuilding, and other tasks using a universal file format (XML-based). By default, all pkt output is in 7-bit ASCII which is UTF encoded and is compatible with XML parsers. pkt files can be disassembled, reassembled, and repaired by hand if necessary. pkt also supports the use of 8-bit compressed XML packets for its archives using one of several compression algorithms. In general, pkt will try to use the best algorithms available.
Industria is a collection of portable R6RS Scheme libraries for cryptography (AES, DES, Blowfish, HMAC, MD5, SHA-1, SHA-2, RSA, DSA, etc.), zip/gzip/zlib decompression, disassembly of amd64 machine code, Off-The-Record messaging, bytevector pack/unpack syntax, TLS connections via custom binary ports, and more.