ccglue is a complementary tool to cscope and ctags. The tool builds a cross-reference symbol database from cscope (and ctags) databases that can be used to display dependency-graphs (aka call-trees, code flow). Visualization can be done with the Vim CCTree plugin or the built-in stand-alone command-line tracer.
yuxtapa is a multiplayer real-time CLI game. It looks like a roguelike, but feels like a multiplayer 1st-person shooter with a focus on team play. The idea is to take the "feel" of such team based multiplayer games as Enemy Territory into an NCurses-based game with roguelike controls. Like roguelikes, yuxtapa is lightweight but surprisingly rich under the crude surface. It features several classes from which to choose, each with a different special ability, randomly generated maps which can also be saved and reloaded, and multiple game modes or objectives.
gwcalc is a front-end for the Wcalc command line calculator. Its main features are menu access to all functions defined in Wcalc, menu access to a huge number of constants defined in Wcalc, intuitive entry of formulas, easy editing and 're-evaluation', and easy conversion between decimal, hex, octal, and binary, both in input and output. It works with fractional numbers in all bases, is very configurable, and is easy to use.