Makefile      automates building from sources, as usual
chess         http://code.google.com/codejam/contest/dashboard?c=619102#s=p2
cyclomatic    counts branching keywords per function in Java-like sources
gitwdiffstat  counts changed words in a git repo
kd            kd-trees
minmodels     finds the minimal models of a CNF formula (aka prime implicants)
pos           char count to line:col
randid        generates random strings of lowercase ascii
quine         quine quine
sat           a simple SAT solver
square        generates bitstrings by merging two copies of a bitstring
vote          effect of threshold on coalition probabilities
zdd           builds a zdd