He told iTWire that while many companies and institutions used such assignment to include contributions in projects of which they were the primary copyright owner and contributor, "they all use divergent contracts, and it would be good to standardise and harmonise those".
Shuttleworth was reacting to queries raised in connection with an article in the Linux Weekly News where editor Jon Corbet had expressed reservations about the Canonical policy. Corbet mentioned that he had asked Canonical some queries but received no answers over the course of a couple of days.
(It must be noted here that Canonical took less than three-and-half hours to provide a detailed response to iTWire's queries; the delay in publishing this article is solely because this writer was on holiday.)
Elaborating on his point, Shuttleworth said, "for example, Intel required copyright assignment for contributions to Clutter and other projects. Novell to Moblin. Red Hat has a number of contributors' agreements too. There's a long list of those agreements; a few of them are poisonous but they are the rare exception.
"The guidance at Canonical is that we encourage our employees to sign copyright assignment agreements for the projects they participate in (as far as I know we've done so for MySQL, Zope, FSF, Novell, Red Hat, Intel and others) in order to facilitate the upstreaming of their work. There are variations on the language used. Canonical's was highlighted in a recent LWN article, but I think the article created the very mistaken impression that Canonical's agreement is materially different from any of the others I've mentioned."
Shuttleworth is the founder of the Ubuntu GNU/Linux distribution and, due to its popularity, every move that Canonical, the company behind it, makes, comes in for intense scrutiny, at times by those with no affiliations, but often by those who are deeply conflicted.
"All copyright assignment agreements empower dual licensing, and relicensing, and as a result such projects attract more investment than other projects which don't create the same opportunities for underwriting companies," Shuttleworth said.
"Canonical's agreement is not in any sense unusual in that regard - except that the folks who wrote it chose to try to reassure people that we are only asking for contributions on projects where we publish a free version. There are variations on the theme - some take a 'licence back' approach rather than an assignment, others use an 'unlimited licence'; those variations seem mainly driven by the preferences of the particular legal department that drew up the agreement."
He said most copyright assignment agreements also included IP clauses to prevent trojan contributions. "Again, there is variation in the language used, but the intent in all cases is the same, and Canonical's approach is, in my view, simpler and cleaner than most.
"If you chat with (FSF legal adviser) Eben Moglen about this, he makes a very compelling case for the dangers to companies of accepting contributions without such an agreement in place - which is one of the reasons the FSF does so."
Shuttleworth said such agreements were easy to demonise. "The most common complaint I've heard is 'why can't a company accept my patches to them under the same licence that they give me the original code?' But that suggests that the two contributions are equal, when they really are not. One party contributes a whole working system, with a commitment to continue to do maintenance on it, the other contributes a patch which is (generally) of no value without the rest of the codebase. "
He said: "The one very interesting grey area is that of plug-ins and extensions, where the contribution could well be a whole work in its own right.
"The only place I've seen that question get ugly, though, is in the OpenOffice.org project, between Sun and Novell (both of which require copyright assignment on specific projects)."
Careful analysis of the real source of contributions to major open source projects would "support the idea that corporate investment and participation in the ecosystem, usually with copyright assignment, has been a major positive force in getting the free software stack to the point where it is today. It's not the dominant factor, but it's vital."
And he took a potshot at some of the whiners, saying: "The folks who appeared to be complaining about Canonical's agreement in the LWN article are the same folks who in the past have said Canonical makes no contribution to the open source ecosystem.
"How ironic that their complaint should centre on a project that Canonical underwrites! They also mostly work for companies that have their own copyright assignment requirements for their own projects.
"I would very much like to see a common contributor agreement, and Canonical would likely adopt standard language that addressed the key points that all the major current agreements address."