Commander Keen source code released
A little slice of history regarding one of the technical foundations of Commander Keen, for those that aren't aware:"Then, the first breakthrough. John Carmack devised a smooth, scrolling routine similar to that used for the background of Nintendo games but never before possible on the PC." [1]The technique is called, adaptive tile refresh. [2][1] http://www.3drealms.com/keenhistory[2] https://en.wikipedia.org/wiki/Adaptive_tile_refresh