C4 (conference)
C4 was a Macintosh software developers conference held in Chicago, Illinois. The conference ran from 2006 through 2009. It was created by Jonathan Rentzsch after the demise of MacHack. In May 2010 Rentzsch announced that he would no longer operate the conference due to a dissatisfaction with Apple's policies toward iPhone OS development and the lack of a strong negative reaction from the Apple developer community.
Read more about C4 (conference): C4