From the organizers:

A conference exploring open source, open tech, and the open web in the enterprise.

All Things Open is the largest open source/tech/web event on the East Coast of the United States. In 2017 more than 3,200 attended from 34 states and 16 countries. In 2018, we’re expecting 4,000+ from all over the world. It is a diverse audience with nearly every major technology company represented.