And for open supers games, I'd also add Vigilance: Absolute Power, which was my FIRST stab at a OGL supers ruleset, before Blood and Vigilance and Supers20.
It's based off the 3.0 SRD and was published in softcover by Mystic Eye Games about 8 years back.
Is tri-stat open? I only know that it's core book was a free download from the GoO site.
Was Vigilance: Absolute Power similar to Blood and Vigilance?
Unfortunately, although Tri-Stat dX could be obtained for free on RPGNow, no iterations of the Tri-Stat system except the d20 versions (Anime d20 and Silver Aged Sentinels) are OGL.
I'm trying to start my own fan but OGL supers project here on EN World:
What kind of Super OGL book would you like?
Relique, what is open content in SAS d20? It says everything in Helvetica, but these are there sample boxes, characters and tables (just the stuff I did expect to be not OGC).
Here is the first design thread:
Designing OGL Supers for d20 modern
There are a few other open superhero games that haven't been mentioned yet. 4C System (a retroclone of FASERIP, the Marvel Superheroes RPG) is the biggest one. It's public domain, so you can do practically everything with it.
You can read more about it and the other open superhero games on the Superhero genre page of the Year of Living Free.