Here are some programs I've made. Several of these are very specific, and
performs a very narrow set of tasks. Pretty much all of them are command-line
utilities, and all programs include source code.

Utilities:

Some small crossword utilities
FACTOR [47 kb], factorize integers up to 2^64.
LBM [57 kb], convert lbm images to bmp (a format not supported by ImageMagick).
TCOMP [20 kb], display differences between two Thunderbird profiles (emails
               only). (windows only)
FOIL [23 kb], calculate the probability of getting k foil cards out of n cards
              on steam. Full formula: (n choose k) * 0.01^k * 0.99^(n-k).
SEED [2 kb], find daily challenges with similar seed for the game Spelunky.
             Chronological summary here and summary sorted by commonness here.
             Warning, the game has been patched and seeds no longer repeat.

Game solvers:

QUARREL [277 kb], find optimal words for the game Quarrel. The included
                  dictionary is smaller than the one in the game.
SEQ [52 kb], find optimal synthesize probabilities in the game Sequence.
             Summary here.

Much more to come later.