Quake Advent Calendar 2013 - Part 4

Welcome to a Quake-themed Advent Calendar. On 24 days 24 people will showcase something about Quake. Something old, something new, something obscure, something you should check out. Monitor the list on the frontpage to see new posts every day. This is part 4 for the 19th to 24th December. See quake_advent_calendar_2013 for the previous posts.