Greenfoot 2.4 is now part of the Rasbperry Pi distro!
If you thought you need a fancy computer to get cracking on your Greenfoot programming, think again!
With just a Raspberry Pi B+ or Raspberry Pi 2, you can already start developing your games right away! Just type in the terminal:
sudo apt-get update && sudo apt-get install greenfoot
and it is availabe in the start menu!