It's not going to printers until mid-April (2013), but FATE Core will be released under both OGL and Creative Commons (probably CC-BY) licensing.
Creative Commons for Fate Core: One of the things we've done with Fate Core is write the rules up from scratch. This got us the clearest text possible. It also meant that absolutely none of our rules text uses text written by someone outside of Evil Hat. With that kind of ground-up ownership of the text, it frees us up to do more than just the Open Gaming License (OGL) if we want -- and the most popular other-license request we've gotten over the years has been for some kind of Creative Commons licensing alternative. With this goal funded, we'll put the time in to make that a reality -- we will choose a commercial-friendly, non-viral license that fits our vision for others using Fate Core (likely CC-BY), and provide documentation for how to properly follow the license if you decide to go that path with your own derived material, as well as protocols for commingling your CC-derived work with others' OGL materials if you happen to design like Frankenstein.
(From the FATE Core Kickstarter, which far surpassed the Creative Commons goal well before it closed.)
FATE Core is designed as a robust but generic system placing emphasis on narrative control, with scalable crunch levels to accomodate the designer's or gamer's playstyle preferences. There are a number of FATE games in fantasy settings if you want to see how it can work in action (the Dresden Files RPG is their flagship production), and the Core release will be accompanied by generic modules and guidelines for designing one's own addons (like magic).
Also worth mentioning that FATE Core will be free to download as a pdf as soon as the physical copies are also available.