Well, I think the play was a tribute show. I looked them up, they are called The Primitive Screwheads.
http://www.primitivescrewheads.com They're a theatre company in San Francisco. That was their first show and now they do all kinds of horror movies live. I guess their known for showering their audiences with fake blood. Pretty cool. If you look at the rest of Robert Selander's youtube page, the guy has tons of other videos where there's all kinds of wierd and funny stuff.
I don't think they made a bunch of money off of Evil Dead or anything either. They seem like just a bunch of poor college theatre kids with a huge love of horror and comedy. I think it's cool.