[beagleboard] Is BeagleBoard/Bone really an Open Source Hardware Platform?

I was looking for the "legal" language around the BeagleBoard/Bone format
before engaging with it.

Check out http://beagleboard.org/hardware/design and the notes on the
SRM and the design materials themselves.

For example, if someone was to design a pin compatible board that didn't use
a Texas Instruments processor,
would TI come aftyer them for it (i.e. sue them)?

Certainly not. Nothing has been done to patent/trademark/etc. the
pinout and TI would not come after you. It would be great to have
other hardware that can make use of http://beagleboard.org/capes.

Just how "Open" is this
small form factor?

Not as open as if it was an open standard--though not all standards
are open. I mean, a lot of the signals are pretty dependent on the
processor's muxing ability.

For a time, the goal was to build an Arduino-compatible header, but it
was too limiting in terms of board size (if you go with the Mega
format) and added too much cost to the design. What was done is what
was seen as a good balance on features and flexibility.

I would compare it to "Arduino" where there are now "Arduino" compatible
boards that
support Atmel, ST, NXP, etc. processors - can this be done with the
BeagleBoard/Bone format?

It can be done, but it is a bit harder, at least if you start using
the many peripherals on the header, such as UARTs, CAN, MMC, LCD,
GPMC, etc., etc., etc.

(And yes, I'm sure that the name "BeagleBoard"/"BeagleBone" is trademarked,
just as "Arduino" is -
but you can call it "XYZ for Arduino" without any legal issues...

SO what' the story here?

We wouldn't like it if you used the BeagleBoard.org, BeagleBoard or
BeagleBone names as a definition of your product, but, as you say, you
can say you've created a "BeagleBone cape", "XYZ cape" or board with a
"BeagleBone-compatible header". You've got the point right that the
difference is declaring your board to work with BeagleBone vs. saying
it *is* a BeagleBone.