The person they have hired to work on porting new games to Linux and Mac is Edward Rudd, who has already brought over a dozen titles to the non-Windows operating systems in the past for earlier Humble Bundle offerings.
Jeffrey Rosen shared this latest Humble Bundle hiring in a new blog post where he was explaining the delay in porting the "Vessel" game to Linux and Mac. "I am proud to announce that Edward Rudd (aka urkle) has just joined our humble team full-time! Edward is one of the most prolific Linux game developers, bringing around 17 Humble Bundle games to Mac and Linux alone. In addition to devoting much more time to bringing games to new platforms, we hope that he will help train more Mac and Linux developers and help grow and direct our porting capabilities."