It looks like the Stock ROM.
I really want an OC kernel for this phone. We currently do not have one, but the source WAS released for this phone so it's possible in the right hands.
EDIT: In build.prop, you should enable hardware acceleration:
Personally, I set all of the stagefrights to true except for http, because doing the http one gives me that green line across the top on HQ YouTube videos.
After making these changes I have noticed a significant performance increase. I have no lag anymore in The Impossible Game, before it was almost unplayable, but thanks to these changes it runs just like my friend's iPod equivilent.