The poor man's daily snapshot, glastree builds live backup trees with branches for each day. Users directly browse the past to recover older documents or retrieve lost files. Hard links serve to compress unchanged files, while modified ones are copied verbatim. A prune utility effects a constant, sliding window. It is implemented as a set of Perl scripts.
Unarc unpacks an archive and creates a top-level directory to unpack into if it's needed. Unarc works with lots of archives, not just tarballs (bz2, zip, and even rpm are supported). There is a companion program arcdir which provides a uniform way to archive directories into tarfiles, zipfiles, etc.
QML (Quantity Modeling Language) is a "thing"-based language for scientific and mathematical data modeling. Each "thing" is a quantity which may be associated with either a structure or physical phenomena. Quantities, in turn, may hold other Quantities or values (numbers or strings). Higher-level data models, which associate or define meanings to various quantities (such as velocity or position), can be built from QML quantities. The higher-level data model (XML) schema that inherits from QML may be understood, and its instance documents may be parsed into QML documents and objects by the QMLReader.
wgrab is a Perl script for for retrieving Web documents from the command line. It allows you to use date-based and/or number-based patterns to specify the documents to download. Regular expressions can be used to restrict which references are to be followed when performing recursive retrieval.
Easylzma is a C library and command line tools for LZMA compression and decompression. It uses Igor Pavlov's reference implementation and SDK. It is meant to be a tiny wrapper and portable build system around a subset of Igor Pavlov's LZMA compression and decompression implementation. The API is small and intended to be straightforward. The project aims to support multiple different prominent LZMA file formats and is focused on producing something that is easy to build and use everywhere.
lcra renames filenames like COMMAND.COM and MAIN.C to more tasteful ones like command.com and main.c. It tries to guess which filenames are DOS-ish ones needing changing, and which are really meant to be uppercase. It will fix the contents of a directory and all subdirectories. The companion program nsra changes spaces in filenames to underscores.