We just put the nascent beginnings of an STM32F peripherals library up on github:
https://github.com/ashima/embedded-STM32F-lib
It’s really early on in the process, but there’s enough there to get UARTS, clock, LEDs, etc. going. New stuff is getting added (we had a XBee streaming commands today). But I think it’s far enough along that if anyone wants to poke their head in and take a look, it won’t bite too hard right now 
Why would we do such a thing? So the point of the library is to get something that’s properly open source available (it’s both open and won’t limit what licenses you would want to put on anything that you build with it); its very traceable back to STM’s data sheets (including catching some errata); it packages stuff as c++ objects; it’s modular in the same way that the STM chip family is modular on the hardware-side (so it should be expandable over the family of STM chips)
We put some basic info in the associated wiki ( https://github.com/ashima/embedded-STM32F-lib/wiki ) and will expand that with time, too.
Hope it’s useful.