OpenSource and how to demo it

Burr is the person who has been preparing, executing and demoing all the Keynote Demos during the last Red Hat Summits.
Red Hat Summit is the yearly event from Red Hat for announcing news and bringing together all of its customers in a huge conference.

I wanted to know from Burr, how he got involved with OpenSource, what it means to demo OpenSource in front of such large audiences, and how demoing OpenSource has changed over that last years and decades.