breveCreatures is a screensaver that simulates the evolution of virtual creatures in a physically simulated 3D world. Beginning initially with random creatures, the screensaver uses a genetic algorithm to develop creatures capable of realistic locomotion behaviors.

The concept and algorithms implemented in breveCreatures are based on Karl Sims´ seminal work, "Evolved Virtual Creatures".

Because the screensaver uses an evolutionary algorithm, it may take a long time—hours, or even days—before effective locomotion behaviors can be observed. Each time it is run, the screensaver will save its progress and continue from where it left off.