It happens mostly in large cities like SF, NY, Austin, Seattle, near where tech center is, Most Hackathons I know attract students and young professionals. There are some more professional hackathons like AT&amp;T&#x27;s. Facebook for example has a FB Hack and you can compete for the trophy at FB Headquarter, I don&#x27;t know the first hackathon but my impression is FB&#x27;s hackathon has turned into a popular icon and everyone soon follows.<p>Major League Hackathon is an organization going around US and now some part of the world to help organize hackathons.<p>I&#x27;ve been to FB&#x27;s, Google&#x27;s, a couple NY Hackathons, MIT Hack, and a few other smaller student-init hackathon events. I basically hear them on twitter, on facebook, or from friends.