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.
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.
The Linux Backup Utility (LBU) is a simple, menu-driven script for performing backups and restoration of data from tars, compressed tars, and tapes. It supports basic hardware compression as well as variable hardware block sizes. It lets you configure tar block sizes, exclusion lists, inclusion lists and it supports wildcards.
Ftwalk is a high level script programming language, very similar to awk, but greatly extended to include a richer type system, object-oriented features, 300+ built-in functions, extensibility through dynamic libraries, etc., which makes it roughly comparable to languages like Perl. It does file tree searches, and was originally used to implement selective redundant copy backup stores. It can be run interactively as a calculator.