Hi folks- I'm Bill Heron, one of the Development Team at Secret Fire Games, the makers of the Secret Fire RPG. It was once known as Legends & Labyrinths, but the name was changed to reflect the fact that it isn't just another D&D clone, and is non-OGL.
Rather than go into a big spiel, George has already compiled a list of what makes TSF (as it known) different here - What Makes THE SECRET FIRE? (fka LEGENDS & LABYRINTHS?) Different? Secret Fire Games?
The Secret Fire is so named because Legends & Labyrinths is trademarked by Justin Alexander, who will shortly be publishing a game under that name.
I assume you guys discovered this when you tried to publish your game as L&L and couldn't.
Half-truths and hidden insults are a sure-fire way to alienate at least one potential customer.