The saying, the perfect is the enemy of the good sums up a lot of Ted Nelson's life.
He has a lot of ideas. They inspire people. He's been working on them for ages. (Xanadu was started in 1960.) But he never is satisfied, he's always changing it, he never releases (OK, an incomplete form of Xanadu was released in 1998...), and the key parts that people care about have been released elsewhere in a form that he doesn't like.
A bit worse than that; from a friend who looked at it:
They didn't do the basic end to end work, so creating a client to display a Xanadu document was almost impossibly onerous. You had to grok and use around 6 different things, and, well, however nice the backend might be, it just wasn't practical.
Also an example of the perils of stealth mode, I found the above believable simply because they'd been in stealth mode for decades.
I compare Ted Nelson to Alan Kay in the continuum of visionaries. They both have and have had far-seeing, inspirational, empowering visions of applied computer technology. They are both, of course, incredibly quotable, even outside IT.
Ted Nelson futzed around and, mostly after the fact, other people discovered that the web was kinda sorta really close to Xanadu, but that it would be really awesome if it had been designed with that vision in mind.
Whereas Alan Kay followed through on predicting the future by inventing it.
I'm still astonished that, even with the backing of Autodesk, we don't even have transclusion as part of the web.
He has a lot of ideas. They inspire people. He's been working on them for ages. (Xanadu was started in 1960.) But he never is satisfied, he's always changing it, he never releases (OK, an incomplete form of Xanadu was released in 1998...), and the key parts that people care about have been released elsewhere in a form that he doesn't like.