Our server is practically vanilla 1.8.3, but it has a minor addition to it in the form of special quiz booths that spit out trivia questions, which you can answer for mats/blocks. This server is basically intended to test our capabilities(server load etc.), and this mod/concept that we're working on.

Currently there are minimal restrictions in place. Please feel free to drop by and give us some feedback in this thread:

http://www.minecraftforum.net/forums/servers/pc-servers/survival-servers/2411920-learncraft-no-whitelist-free-for-all