I wonder how well an open source Minecraft clone like <a href="http://www.minetest.net">Minetest</a> would work with some of the things teachers are using Minecraft for? It looks like one of the lessons mentioned in the scpr.org article is using a mod on top of Minecraft (the Forestry mod for bee keeping), so, at present, Minetest couldn't be used for that, but educational mods could be developed for Minetest.
Fedora with CentOS for a virtual machine development web server and Debian for Koha and Evergreen virtual machines.