GameBots is a project started in early 2000s by A. N. Marshall and G. A. Kaminka. The project aims at providing researchers a real-time virtual environment testbed for their agents. GameBots utilized environment of Unreal Tournament first-person shooter game providing several scenarios for the agents. GameBots project was continued by several research groups resulting in many interesting applications. In this paper we summarize evolution of the GameBots project and contributions made since the first appearance. We focus on Pogamut GameBots branch which has been steadily developed for six years with many improvements and optimizations.