If i understand you right you modify the libs so they work with Teensy
that they would no longer work on an Arduino Board?
Oh no, not anything like that!! I always aim to preserve compatibility.
In fact, in the process of porting to Teensy, I often find libraries that were hard-coded to work only with the 168/328 chips. I usually add support for Arduino Mega and Sanguino too. For example, the Firmata library, which is now pre-installed on every Arduino Uno and Arduino Mega, became compatible with the Mega boards only because of my work to add a hardware abstraction layer.
To get an idea of the type work I've done, take a look at libraries/Firmata/Boards.h inside your arduino-0022 directory. Several other libraries work on Arduino Mega only because of the Teensy porting effort!
I always attempt to contact the original author(s) and contribute my changes. Usually, when I can find the author's contact info, they publish the changes in a new version. In some cases, I've discovered and fixed bugs too (eg, OneWire was horribly buggy). In a few cases, it's turned out the library was pretty much abandoned code and I've become the de-facto maintainer.
Recently some of the hardware abstractions I've developed for libraries are (finally) being included into the Arduino core. Some libraries (eg, SDfat) have also made use of hardware abstractions I've proposed but haven't (yet) been accepted by the Arduino Team.
I definitely do not patch libraries to work exclusively with Teensy, and in most cases I've gone to quite a lot of extra effort to build robust hardware abstraction layers that support many boards and allow for new boards to be added easily.
Then again, some libraries are already very portable, so all I do it test and document.
But nice to see someone else had the same idea and made a central list for a 3rd party board.
If you know of any way to support this application i would be happy.
I'll take a look at Ardulibrary soon. Maybe I could publish a page in the format it expects, so it could query the list I have?
Or if there's more work to create a central list, at least the work I've done so far might help. I only tend to test/port/document the "major" libraries. But a quick look at my list shows several that aren't on the 2 lists I saw mentioned in this thread.