There are varying degrees of open. The Savage Worlds licensing procedure, for example, is significantly less open than that of d20 derived products, which use the OGL as their baseline, and which don't require review, submission, or anything other than following the terms of a license which is freely available to anyone who wants to come along and use it.
There's also a True20 license. Fudge was already open using a difference licensing structure before the OGL was active, as was Dominion Rules and Circe... although to be fair, all of those (with the possible exception of Fudge) are really quite obscure and indie, especially relative to the OGL. Fudge also led to FATE, which seems to have a fair bit of traction, including being the system behind the Dresden Files RPG and Gorilla Byplane Attack. Err.. I mean, Spirit of the Century.
I think a bunch of the current Mongoose games are open, which include new iterations of classics like RuneQuest and Traveller.