The interactive portion of the annual South by Southwest (SXSW) festival is officially under way today in Austin, Texas. While tech geeks, hungry startups, eagle-eyed investors and celebrities decend on the funky city over the next several days, there are several keys to keep in mind.

No doubt, SXSW has evolved dramatically from the simple music festival that launched in 1987. Today it includes a film festival and interactive event. The interactive portion alone attracts people from all types of industries -- software development, social media, venture capital, marketing, you name it.

And attendees span all types of demographics. In the infographic below, the folks at social branding company Activ8Social try to make sense of the insanity that is SXSW:

Click to Enlarge+
Evolution of SXSW (Infographic)