Ted Nelson and Andrew Pam have come out with The Little TransQuoter, a simple (and currently fairly rudimentary) system for doing transclusion of text blocks on top of HTML (see sample).
The concept of transclusion — the quotation of documents by linking directly to embedded text instead of making a copy — has a lot of interesting possibilities, but in the end it feels to me like it’s going in the exact wrong direction for the digital age. Nelson’s whole design seems to be based around the idea of ownership: I own the bits I’ve written, I control the content and modifications, and when you quote from me you owe me a micropayment. That was the shape of publication in the last century, but it’s not how 21st-century publication is shaping up. In so far as ownership means control, information in the 21st century has no owner. Information can have hosts, pedigrees, histories, and even generally-accepted custodians, but in the future that’s being built “my bits” means not what I’ve written but what I’m carrying in my hard drive. Like a new joke or a bad cold that travels around the office, mutating as it goes, each copy of information is controlled by the host that holds it in his possession. I can’t see any technology that tries to buck that trend winning out in the long run, especially not as we ride the technology trends towards the day when I can store the entire Web in my pocket.