BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.
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.
f/Calc is a utility to calculate lens formulae for photographers so you can focus on the artistic bits rather than on the mathematics behind it all. f/Calc can do "f" number arithmetic, and can calculate depth of field, hyperfocal distance, the field of view of a lens, the angle of view of a lens, magnification, and how the focal length of the lens on the camera changes the way the spot metering function works. In addition to the Unix/Linux Tcl/Tk version, there are native Windows, Palm OS, and Macintosh versions as well.
Hanzim ("Hanzi Master") is an interactive visual dictionary for learning and seeing relationships between Chinese radicals, characters, and compounds. All the characters with a given radical, phonetic component, or pronunciation can be displayed, and all words containing a character, with English meanings. All data is stored locally. Either simplified or traditional characters can be used.
hfsutils is a comprehensive software package being developed to permit manipulation of HFS volumes from UNIX and other systems. HFS is the ``Hierarchical File System,'' the native volume format used on modern Macintosh computers. The software reads and writes HFS (but not HFS+) volumes with several command-line programs and optionally an X interface. The software can also be used as a C library.
NetPlug is an extensible multi-connections, multi-protocol, network client program, written in pure Tcl/Tk. Includes a complete Irc client plug in that you should love if you like IrcII 'classic' look & feel (plus customizable style/colors scheme, sound,... Now includes full DCC support (with GUI), ircII like aliases and improved scripting (Tcl!), keywords (your nick...) highlighting, and more
OpenVerse is similar to other graphical chat systems like Excite Chat and Microsoft Chat, with the main differences being that OpenVerse is open source software, has no advertisements, and also runs on a variety of systems including Windows, Unix, Macintosh, and just about anything else for which you can find a copy of TCL/TK.
SMM++ Mud Client is a mud client with extended and unique features. Aside from all standard mud client functionality like ANSI color support, aliases, action triggers, and tab-completion, SMM++ features a highly-customizable user interface (labels, buttons, and menus) and unique and powerful mapping capabilities, and SMM++ is the only mapping crossplatform (Tcl/Tk based) mud client available.