cfv is a utility to both test and create .sfv (Simple File Verify), .csv, .crc, .md5(sfv style), md5sum, BSD md5, sha1sum, and .torrent checksum verification files. It also includes test-only support for .par and .par2 files. These files are commonly used to ensure the correct retrieval or storage of data.
Pysync has both a demonstration implementation of the rsync and related algorithms in pure Python, and a high speed librsync Python extension. The pure Python is not fast and is not optimized, however it does work and provides a simple implementation of the algorithm for reference and experimentation. It includes a combination of ideas taken from librsync, xdelta, and rsync. The librsync Python extension is less flexible and harder to understand, but is very fast.
python-fchksum is a module used to find checksums of files (or stdin). It supports md5, crc32, cksum, bsd-style sum, and sysv-style sum. The advantage of using fchksum over the Python md5 and zlib(.crc32) modules is both ease of use and speed. You only need to tell it the filename, and the work is done by C code.
Xfiles is an interactive utility for comparing and merging one file tree with another over a network. It supports freeform work on several machines (no need to keep track of what files are changed on which machine). Xfiles can also be used as a cross-validating disk<->disk backup strategy.
BitTorrent is a tool for copying files from one machine to another. FTP punishes sites for being popular. Since all uploading is done from one place, a popular site needs big iron and big bandwidth. With BitTorrent, clients automatically mirror files they download, making the publisher's burden almost nothing.
Spana/Panorama is a protocol and a reference implementation for a new peer-to-peer network with the primary goals of providing anonymity and a robust network. Some of the implemented features are: anonymous file transfers (on both ends) and news (NNTP), RSA-based virtual identities for file authentication, advanced file indexing for searching (such as on bit rates), and automatically resumed downloads from multiple hosts using cryptographically strong checksums on files (cf. heuristics based on filenames) for security and flexibility.
BitTorrent Queue Manager is a console-based BitTorrent client running on top of BitTornado that provides built-in queue management functions. It also provides a remote interface compatible with ABC for Web-based control. Furthermore, peer information can be queried, including country and network names, and a built-in crawler can gather new torrents on specified trackers or catalog sites for downloading automatically.
Anatomic P2P is an implementation of a protocol designed to decentralize BitTorrent. It is based on a network of "supertrackers" or "supernodes" that users query and which route users to the correct tracker(s). A modified tracker and client are used, and "old" clients can still use the network. The technology is based on the Gnutella GWebCache system.