astateful is a unique approach to Web development. It incorporates a solid theoretical foundation based on Dynamic Programming in which a Web site is programmed in such in a way that it can be "solved" using a 'top down' or 'bottom up' approach. It is very scalable. Caching and encryption are included by default. It has a steep learning curve.
PalindromicPrimeFinder is a little "toy" program that can find relatively big (e.g. 1000-2000 digits) palindromic probable prime (PRP) numbers. It generates random palindromic numbers and tests them for primality using a probabilistic algorithm. It is multi-threaded and stops after a certain timeout (if no palindromic primes are found).
Devilspie2 is a utility to find windows and changes properties of these windows with the help of rules written in LUA. For example, you can make a window of an application always appear at the same screen position each time it starts. It is a continuation of the program Devilspie, written by Ross Burton.