ClassyTcl is a dynamically loadable object system for Tcl. Both a Tcl-only and a C implementation are available. It also doesn't require patches to the Tcl core, which makes installation and maintenence easier. Performance is quite adequate. The C version is gives extra speed, and makes it possible to implement some methods in C. In contrast to other object systems for Tcl, it is not modeled after the object system designed for a completely different language, such as C. The system is simple but flexible. Classes and objects are dynamic, and can easily be queried, changed, and debugged at runtime.
e4Graph is a C++ library that allows programs to store graph-like data persistently and to access and manipulate that data efficiently. With e4Graph, you can arrange your data in the most natural form that reflects the relationships between its parts, rather than having to force it into a table-like format. The e4Graph library also allows you to concentrate on the relationships you want to represent, and not on how to store them in a database. You can modify data items, and add and remove connections and relationships between pieces of data on the fly. e4Graph allows you to represent an unlimited number of different connections between pieces of data, and your program can selectively manipulate the data according to the relationships it cares about, not having to know about other connections represented in the data set.
Ficl (Forth inspired command language) is an ANS Forth interpreter written in C. Unlike traditional Forths, this interpreter is designed to be embedded into other systems as a command/macro/development prototype language. Ficl provides object extensions that can be used to wrap methods and structures of the host system without altering them.
GNUlpr version 1.0 is a complete printing system based on LPR, and provides support for printer-specific options, GUI tools, and autoconfiguration. The 1.1 tree is a completely re-thought printing system. Rather than creating an all-powerful spooling daemon, it constructs a pipeline of "filter" programs to perform tasks (spooling, data stream type conversion, authentication, network protocols, etc.).
Memchan is an extension library to the script language Tcl, as created by John Ousterhout. It provides two new channel types for in-memory channels and the appropriate commands for their creation. They are useful to transfer large amounts of data between procedures or interpreters, and additionally provide an easy interface to on-the-fly generation of code too. No need to set or append to a string, just do a simple puts.
The Snack sound extension adds commands for sound play/record and sound visualization, e.g. waveforms and spectrograms. It supports in- memory sound objects, file based audio, streaming audio, WAV, AU, AIFF, and MP3 file formats, synchronous and asynchronous playback. The visualization canvas item types update in real-time and can output postscript. New commands and file formats can be added using the Snack C-API.