Ultrastudio.org is an educational site built along the lines of “encyclopedia that anyone can edit” that allows to user written Java applets as an illustrative material. It combines a Wiki engine, code reviewing system and security-aware Java compiler. Most of the applets are available under various open source licenses (the absolute majority under GPL).

Source code repository at Kenai.com only contains code that we either wrote themselves of normally if the author has been contacted and responded with approval, so it has less applets than available directly from the site.