Tcl provides a portable scripting environment for Unix, Windows, and Macintosh that supports string processing and pattern matching, native file system access, shell-like control over other programs, TCP/IP networking, timers, and event-driven I/O. Tcl has traditional programming constructs like variables, loops, procedures, namespaces, error handling, script packages, and dynamic loading of DLLs. Tk provides portable GUIs on UNIX, Windows, and Macintosh. A powerful widget set and the concise scripting interface to Tk make it a breeze to develop sophisticated user interfaces.
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.
Ayam is a free 3D modelling environment for the RenderMan interface. It features good RIB export, CSG (all RenderMan primitives supported), and NURBS modelling. Features instancing, arbitrary number of modeling views, object clipboard, independent property clipboard, n-level undo, console, and Tree-View with Drag-and-Drop support.
MacPorts makes the world of open source software available to your Mac. There are over 5600 software titles ("ports"), each one installable with a single command. This is probably the biggest, most up to date open source software collection for Mac OS X. MacPorts works much like the ports collections of the major BSD operating systems.
Tk Drag and Drop is an extension for Tcl/Tk to add native drag and drop capabilities to the Tk toolkit. It is designed for Tk versions 8.3.3 and higher. Native drag and drop are supported under Microsoft Windows (XP, Vista, 7), Mac OS X Leopard (Cocoa framework), and Linux (XDND, drag support missing).
TclDTrace is a binding of libdtrace to the Tcl programming language. DTrace is a system profiling suite created by Sun Microsystems. It allows the user to profile a program without modifying its text, or even without the need to distract it if it is running. It consists of a set of library hooks called "providers", a set of tools, a C API (libdtrace), and its own specially crafted scripting language called D. A Tcl binding to libdtrace will allow users to run D scripts and process their results directly from Tcl.
Sudokut is a command line solver for Sudoku puzzles. When supplied with a Sudoku string or file, it returns all possible solutions. It takes approximately half a second to solve a medium force Sudoku by using an efficient algorithm that is guaranteed to find all the solutions. It accepts many options that implement various features (validity check, diff, suggestions, and probing).
Univert is a Universal Unicode Converter, at least as universal as the Unicode implementation in Tcl 8.1 or later can manage on your computer. Univert will convert interchangably between the following formats: native Tcl unicode, hex bytes or words separated by spaces, decimal bytes or words separated by spaces, HTML entities, UTF-8/URL encoding, quoted printable with whatever the current encoding is, and C string with whatever the current encoding is.