Using current greenfoot on Ubuntu 12.04 / 32bit, Oracle Java 1.7. I've installed both firefox and google-chrome. I am unable to right click "openDocumentation" on classes like "Actor" or "World": This yields no result at all regardless whether web browsers have already been started or not. Regarding bluej I found: browserCmd2=firefox $ browserCmd1=firefox -remote openURL($) Adding these to my ~/.greenfoot/greenfoot.properties file does not yield any observable difference. In http://www.greenfoot.org/version_history a corresponding bug is claimed to have been fixed (Fixed bug: Could not open documentation for Actor and World.) in Greenfoot 1.5.3 / 15. July 2009. So far I cannot subscribe to that point of view.