Games played directly inside the web browser have many benefits. Browser games do not need software installation. Furthermore since the web has become the ultimate collaboration environment, the games are available for numerous players that can play in collaborative fashion. Through history online communities have birth alongside with browser games. Nowadays online communities have achieved massive user numbers and those can be important part of the browser game itself. This article targets at analyzing and categorizing of browser games. We also discuss financial opportunities relating to browser games and technologies used in those.