Drawing your ideas to a piece of paper is easy, but drawing onto the screen using the mouse appears to be quite complicated. This usually results in some non-formalised, bad-looking scribbling that is hard to extend and which makes it hard to modify or delete fragments. Currently available web-based whiteboard tools support common drawing features. How- ever, in informatics, teams enjoy the advantage of formalised languages (e.g. UML), which whiteboards do not support and, hence, do not make this advantage effective. For supporting brainstorming processes, we developed a simple, extendable chat ap- plication that can be embedded into existing learning environments through a Web ser- vice framework and focuses on a cooperative modelling approach instead of cooperative drawing.