There's a medtech and health-IT cluster as well, partly due to Emory's med school, and Atlanta being a regional hospital center. Much of that's b2b too (though there are a few Fitbit-style b2c health-IT companies), but different set of people than most b2b companies are, and with its own set of startup incubators (Neurolaunch, Sling Health Atlanta, Global Center for Medical Innovation, etc.).

Random example companies: http://www.virtuallybetter.com/, http://safeheartus.com/