Analysis of voxel collection class strategies. Also see other voxel related posts on this site:
http://0fps.net/2012/01/14/an-analysis-of-minecraft-like-engines/
In Eclipse, using a key command to commit only works when the editor is not in focus (i.e. you have to click on the Package Explorer).
To fix this:
http://stackoverflow.com/questions/3400185/svn-key-bindings-not-working-in-eclipse
(Note: first step is: Window > Customize Perspective)