CPAL is not an Open Source poison pill for Facebook
From the 'holier than thou' files:
A pair of my colleagues forwarded me a pitch today titled, " Disappointing: Facebook Does Open Source like Microsoft." It's an 'interesting' email pitch -- it's a pity I wasn't contacted directly.
Essentially what the pitch (which came from Bob Bickel Founder,
"The poison pill in this license agreement is that anyone using the Facebook code
as part of something else, and puts that up on a website, would need to make all
of the code open source," Bickel wrote in his email pitch.
First off the CPAL is a bona fide Open Source license approved by the OSI. It fulfills the requirements of the Open Source Definition as determined by the OSI and it is the Real Deal.
The ideal of contributions is pivotal to the success and long term survival of the Open Source community, and that shouldn't be thought of as a poison pill in my view. That said not everything that Open Source touches should in turn become Open Source itself. The risk of infection from GPL licensed code (and the GPL is significantly more reciprocal in nature than the CPAL) is significantly higher.
I'm not a lawyer - and I don't pretend to be one - but just because I use Linux doesn't mean that anything I use Linux with (and the Linux kernel itself is GPL) automatically becomes Open Source -- It just doesn't work that way.
Yes the LGPL (Lesser GPL) that companies like Ringside use has additional protections and it doesn't necessarily require attribution (which is the issue that some have trouble with). The CPAL attribution basically means that users need to attribute where the code came from (I've heard this referred to as 'badgeware' sometimes).
The holier than thou - My License is More Open Than Your License - debate is one that doesn't serve Open Source in my opinion, it's one that only serves to fuel the commercial closed source vendor FUD fire. (Though I do think there is a need and a use case for both reciprocal and BSD-type licenses as well as CPAL -- where usage depends on circumstances and one size does not fit all).
Frankly and practically, I think it's a marvelous thing that the Facebook Platform is under a real Open Source license - arguing about the semantics of reciprocity and attribution - diminish the fact that it is an open platform that anyone (without the need for special agreements or licenses) can use/extend and deploy. That's the promise of Open Source and it's one that Facebook is now embracing.