papercut is command line based rock, paper, scissors game for Unix based operating systems like GNU/Linux, BSD, etc. A user can play the game by entering their choice of rock (R or r), paper (P or p), or scissors (S or s). papercut also stores user statistics, i.e. number of wins, losses, and draws.
The Noble Ape Simulation is a collection of a number of autonomous simulation components including a landscape simulation, biological simulation, weather simulation, sentient creature (Noble Ape) simulation, and a simple intelligent-agent scripting language (ApeScript). Noble Ape also contains a social simulation where the Noble Apes can be tracked in terms of social groups and also over many generations to explain social phenomenon to users looking to study this kind of interaction. It has been in development for more than a fifteen years.
Gravit is a gravity simulator. It uses Newtonian physics using the Barnes-Hut N-body algorithm. Although the main goal of Gravit is to be as accurate as possible, it also creates beautiful looking gravity patterns. It records the history of each particle so that it can animate and display a path of its travels. At any stage you can rotate your view in 3D and zoom in and out. Gravit uses OpenGL, Lua, SDL, SDL_ttf, and SDL_image.