4digits is a guess-the-number puzzle game. It's called Bulls and Cows, and in China people simply call it Guess-the-Number. The game's objective is to guess a four-digit number in eight tries, using as little time as possible.
Memoreek is a memory puzzle starring Linux distributions, open source tools, and programming languages.
A style and grammar checker for English, Polish, German, and other languages
A shell library intended for Unix sysadmins.