As everyone has said, its a modified D20 system. It's quick, you really only need 20 siders to play it, and the classes provide a highly customizable method of character creation and development.
Oh, and if people would point or punch if they saw the cover - don't worry, it's a available in PDF. Print it out, remove the romantic fantasy setting section and put it in a blank binder - you'll be fine.
As for not being compatible with core D&D - that's true as far as you couldv't easily mix the class and arcane skill systems with a standard D&D run easily. But it has a good conversion appendix so that you could convert just about any rule, beasty or item into it as you see fit.
Since it's arcana (magic system) is based off of Green Ronin's Psychic's handbook, the resource provides additional arcane skills to draw from, and the similarities in toughness system to Mutants & Masterminds make it a very flexible variant system.
That system in fact is really so streamlined and capable that one could easily use it in many genres, its cleaned up arcana system and duality based alignment system is perfect for Star Wars and similar morality play sort of genres.
If you want to get down to basic numbers, reduce your die rolling, still have vast customization of your character's abilities while still playing D20 and allowing all that D&D stuff to be useful with a new system with limited conversion issues, you might want to check it out.