I think more disturbing might be the precondition in the second paragraph
below that states that if you, as a licensee, implement XPointer, you've
giving them, and anybody else they deem acceptable, the rights to
redistribute it in any way they wish. In effect, a type of enforced open
source. It may be that they're enclosing a poison pill for Microsoft. I
can see Sun's point, but it would make me think twice before I spent
development costs on an implementation.