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.
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.
expect-lite is an quick and easy command line automation tool. Written in expect, it is designed to directly map an interactive terminal session into an automation script. expect-lite scripts use special character(s) at the beginning of each line to indicate the action. Basic expect-lite scripts can be created by simply cutting and pasting text from a terminal window into a script, and adding '>' '<' characters. No knowledge of expect is required. Expect-lite is targeted at the verification testing environment, and will produce a Pass/Fail result at the end of the script. However, its use is not limited to this environment. It includes a powerful debugger with breakpoints, step/skip, and the ability to copy/paste expect-lite lines right into a running script.
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.
Poet (Prototype Object Extension for Tcl) is an OOP extension for Tcl/Tk featuring prototype-based inheritance, constraints, and persistence. It includes Poetics (Poet Integrated Construction Set), a set of tools for end-user inspection and modification of a running Poet application. The current Poetics tools are an object browser and a syntax-highlighting code editor. Poet is available wrapped as a starkit that can be used to load Poet into Tcl or standalone to demo and install Poet.
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).