BlockOS is an add-on for Blockland designed to appear is a mock operating system. It changes the whole look and feel of the main menu by displaying everything in a desktop environment. All key functionality is retained; you are still able to join and start servers, change your name and key and even access the RTB overlay without using the keybind.
A key feature of BlockOS is it's app functionality; users can download these 'mini add-ons' from the built in App Store straight onto their desktop. Each app consists of a GUI, icon and script ranging from screenshot management to music players. Users can also submit their own apps into the store after signing up at http://blockos.nullable.se
The BlockOS team have put a lot of thought into ways to customize the new main menu, ways to do this include full skinning support and custom background selections
http://blockos.nullable.se/ App store