Danny Weitzner, of W3C (someone who's work I know of and respect), recently posted an article entitled "Whose Name is it Anyway? Decentralized Identity Systems on the Web". In it, he suggests XRI "should be avoided at all costs." The main point he makes is that its centralized registries should be avoided, which I won't discuss here.
The statement I find most disturbing is the IPR FUD-bomb he drops:
XRIs ... (come) with a great deal of patent licensing uncertainty.
I'm not sure what "uncertainty" Mr. Weitzner is talking about, but merely stating that "uncertainty" exists, without supporting facts, is exactly what the "U" in FUD refers to.
In the context of the IPR discussions taking place around OpenID, making such a patently false (pun intended) comment strikes me as irresponsible, at best. At worst, its comes off as classic, vile FUD: a recognized expert using their stature and position of influence to sway observer opinion without any basis in fact.
That being said, I will give Mr. Weitzner the benefit of the doubt, and assume he's really just misinformed - or perhaps that the communication of the IPR around XRI is confusing - or even that he finds it somehow "uncertain". But I would ask him for a more responsible summary of the IPR around XRI in his public communications.
All the parties involved in XRI have tried very hard (and I believe, successfully) to make the IPR situation crystal clear: free and open, do with XRI what you want. There's open source implementations on the server side and client side, there's no royalties, etc.
The IPR statement for the XRI TC is here . The TC is operating under the RF on limited terms, which is the most open-source friendly and open licensing IPR mode an OASIS TC can operate under.
If anyone has any concerns about the IPR state of XRI, please let me know directly! If there are problems, we want to fix them. If you have questions, I want to answer them. Please ask us directly instead of relying on statements made by 3rd parties like those in the article mentioned above.