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.
The Helix Ribosome build system is a set of programs written in the Python programming language which provide a common interface to retrieving and building programs from source code stored in a CVS repository. The build system is made up of two basic subsystems. The first ("build") calculates the dependencies of a target, retrieves the source code, and runs commands to build that source code in the correct order. The second component ("Umake") is a cross-platform Makefile generator, which generates makefiles that work with MSVC, CodeWarrior, and typical Unix toolchains. Umake can be used independently from the build program.
The par utility creates and manipulates PalmOS database (.pdb) and resource (.prc) files. Par is designed to be a Swiss army knife for managing these files. It's a command line tool, and not for the faint of heart, but it's very handy and replaces a bunch of little utilities that you might otherwise use.