The lead designer of Dungeons & Dragons co-designed another game published by what company? 
Rob Heinsoo:  Heinsoo was the lead designer on the 4th Edition of "Dungeons & Dragons" (2008), and is co-designer of the 13th Age roleplaying game along with Jonathan Tweet. 13th Age: 13th Age is a d20 fantasy tabletop role-playing game, designed by Rob Heinsoo (lead designer of "Dungeons & Dragons" 4th Edition) and Jonathan Tweet (lead designer of "D&D" 3rd Edition), and published by Pelgrane Press.
Pelgrane Press