Martin Roesch is one of the most successful entrepreneurs ever to build a company based on open source software. Roesch is the author of Snort, which he claims is the "most-widely deployed" intrusion detection software in the world, and the founder of Sourcefire, a network security services provider that uses Snort as the centerpiece of its operations. Last week, the Tech Council of Maryland named Roesch its Commercial IT Executive of the Year.