The other books on hardware from this timeframe such as Tracy Kidder's _The Soul of a New Machine_ or Jerry Kaplan's _StartUp_ or Andy Hertzfeld's _Revolution in The Valley: The Insanely Great Story of How the Mac Was Made_ (available as: https://folklore.org/0-index.html) are quite striking and forthright in their discussion of hardware limitations and the ingenuity needed to get things done.
Or, contrast the far more prosaic _Weaving the Web_ by Tim Berners-Lee and esp. take note of compromises such as URL changing from Universal Resource Locator to Uniform Resource Locator.
If git's pack index gets refactored slightly, it can do anything from trigram-indexed search to metadata indexing to hyperlinking both ways across repos. That is actually useful, I use it: https://replicated.live/blog/wiki
I first read about Xanadu very early in my life, and this project is an absolute miracle in terms of how much it can hold my interest for something that could not and never would work.
The crazy irritating zig-zagging split document view has always struck me as a demo that would be rounded off after "initial release", because it's still a useful feature underneath the stupid viewer-friendly UI. Anyone who has ever reviewed a Git PR or negotiated a contract has already had to do what Xanadu was built to do. It's just that lawyers and programmers invented user interfaces that actually make sense for that, while the Xanadu version is hyper-optimized for the worst possible case.
Still, it is reasonable to assume that once people start writing documents "Xanalogically" - i.e. online, in the way of a Wikipedia article - that there would be a need for a viewable history of one's edits, and that someone might want to reply to a document with inline commentary. It's really everything else that didn't make it into WorldWideWeb or WikiWikiWeb that makes my head spin.
Like, how could two-way links work? I mean, they can't, obviously? Links go around text, so they have to live on a document. The author here mentions spam, but there's a far simpler structural problem that making links two-way means the links have to be stored... say it with me folks, as a stream of annotations on top of the underlying text! Links would go "on top of" your document, linking word 153 of paragraph 4 of document A onto word 96 of paragraph 13 of document B.
But what happens if document B changes? Then it's going to have invalid backlinks! Well, it does work, because in Xanadu... all the documents you write would be transclusions of a "permascroll". Everything you ever write goes in the permascroll and then your Xanadu client would transparently publish a transclusion of your edited document. So "word 96 of paragraph 13 of document B" somehow gains actual referential integrity across changes to the document.
It is the most NLE-ass idea ever, and I didn't make the connection to video editing until you mentioned Ted having Hollywood ambitions. Because basically every video editing tool on a computer ever is extremely Xanalogical. In a Hollywood shoot or a TV show, you basically keep your cameras rolling throughout the shoot, you mark off your shots with a clap board, and then the editor assembles an actual timeline from the source footage. During this process everything is nondestructively transcluded right up until the final export[2].
But, even then, there is no way in hell I could go and transclude someone else's movie straight from their source footage and make a commentary on it. Like, not even in today's environment of YouTube video essays longer than the films they're talking about. It just wouldn't be possible, not for technical reasons but legal ones.
If Ted had actually made it into Hollywood, he would have learned that every reuse of one's work needs to be individually negotiated by a team of lawyers, no matter how petty the use, because all the suits running Hollywood are Valentian rapists[1] (if not actual rapists) who will take advantage of you the moment you provide any leeway. Anyone who doesn't understand this gets taken advantage of until they burn out or fight back. There is no world in which copyright is respected but I'm also allowed to publish a book containing half of your book without your permission. The law saying you're not allowed to do this is older than the US Civil War and decided in a court case[0] that singlehandedly turned copyright from a straightforward inquiry into an insanely fact-intensive question that never gets resolved.
Of course, this was supposed to have been pre-negotiated, which almost makes sense if Xanadu was just weird futuristic Lexis-Nexus, but Ted Nelson also wanted this thing to be an open standard. This would have made piracy extremely straightforward! And I think that's what makes Xanadu so interesting. It's trying to do literally everything and spending comical amounts of effort at it, inventing insane things like Enfilades and tumbler numbers[3], all to fall flat on its face with nothing to show for it.
[2] Of course, in 1960 NLEs didn't exist. Film (and video) was edited destructively with actual scissors and splices.
[3] I legitimately thought tumblr was named after these things for like years but it turns out, no, it's named after a "tumblelog" which is basically proto-Twitter.
Also not to be confused with the 1980 film starring Olivia Newton-John with a great soundtrack by her, Electric Light Orchestra, The Tubes, and Cliff Richard.
The other books on hardware from this timeframe such as Tracy Kidder's _The Soul of a New Machine_ or Jerry Kaplan's _StartUp_ or Andy Hertzfeld's _Revolution in The Valley: The Insanely Great Story of How the Mac Was Made_ (available as: https://folklore.org/0-index.html) are quite striking and forthright in their discussion of hardware limitations and the ingenuity needed to get things done.
The book _CAD History_, available on-line at: https://www.shapr3d.com/history-of-cad/introduction has a bit on Xanadu from the Autodesk end of things.
Or, contrast the far more prosaic _Weaving the Web_ by Tim Berners-Lee and esp. take note of compromises such as URL changing from Universal Resource Locator to Uniform Resource Locator.
Racing the Beam is another one, about the design of the frame buffer-less Atari 2600.
I really like the analogy of “pinball” from _The Soul of a New Machine_. It matches my imagination of good engineers perfectly.
I always believed that side-by-side diff view is a transclusion interface.
Also, permalinks can work on top of git quite nicely https://replicated.live/blog/link
If git's pack index gets refactored slightly, it can do anything from trigram-indexed search to metadata indexing to hyperlinking both ways across repos. That is actually useful, I use it: https://replicated.live/blog/wiki
CRDT merges are a very incremental and useful upgrade for git https://replicated.live/blog/meta
Xanadu-like functionality is perfectly within reach.
We don't get what we want or what we need. Instead, we move erratically in very small, easy, local steps.
I first read about Xanadu very early in my life, and this project is an absolute miracle in terms of how much it can hold my interest for something that could not and never would work.
The crazy irritating zig-zagging split document view has always struck me as a demo that would be rounded off after "initial release", because it's still a useful feature underneath the stupid viewer-friendly UI. Anyone who has ever reviewed a Git PR or negotiated a contract has already had to do what Xanadu was built to do. It's just that lawyers and programmers invented user interfaces that actually make sense for that, while the Xanadu version is hyper-optimized for the worst possible case.
Still, it is reasonable to assume that once people start writing documents "Xanalogically" - i.e. online, in the way of a Wikipedia article - that there would be a need for a viewable history of one's edits, and that someone might want to reply to a document with inline commentary. It's really everything else that didn't make it into WorldWideWeb or WikiWikiWeb that makes my head spin.
Like, how could two-way links work? I mean, they can't, obviously? Links go around text, so they have to live on a document. The author here mentions spam, but there's a far simpler structural problem that making links two-way means the links have to be stored... say it with me folks, as a stream of annotations on top of the underlying text! Links would go "on top of" your document, linking word 153 of paragraph 4 of document A onto word 96 of paragraph 13 of document B.
But what happens if document B changes? Then it's going to have invalid backlinks! Well, it does work, because in Xanadu... all the documents you write would be transclusions of a "permascroll". Everything you ever write goes in the permascroll and then your Xanadu client would transparently publish a transclusion of your edited document. So "word 96 of paragraph 13 of document B" somehow gains actual referential integrity across changes to the document.
It is the most NLE-ass idea ever, and I didn't make the connection to video editing until you mentioned Ted having Hollywood ambitions. Because basically every video editing tool on a computer ever is extremely Xanalogical. In a Hollywood shoot or a TV show, you basically keep your cameras rolling throughout the shoot, you mark off your shots with a clap board, and then the editor assembles an actual timeline from the source footage. During this process everything is nondestructively transcluded right up until the final export[2].
But, even then, there is no way in hell I could go and transclude someone else's movie straight from their source footage and make a commentary on it. Like, not even in today's environment of YouTube video essays longer than the films they're talking about. It just wouldn't be possible, not for technical reasons but legal ones.
If Ted had actually made it into Hollywood, he would have learned that every reuse of one's work needs to be individually negotiated by a team of lawyers, no matter how petty the use, because all the suits running Hollywood are Valentian rapists[1] (if not actual rapists) who will take advantage of you the moment you provide any leeway. Anyone who doesn't understand this gets taken advantage of until they burn out or fight back. There is no world in which copyright is respected but I'm also allowed to publish a book containing half of your book without your permission. The law saying you're not allowed to do this is older than the US Civil War and decided in a court case[0] that singlehandedly turned copyright from a straightforward inquiry into an insanely fact-intensive question that never gets resolved.
Of course, this was supposed to have been pre-negotiated, which almost makes sense if Xanadu was just weird futuristic Lexis-Nexus, but Ted Nelson also wanted this thing to be an open standard. This would have made piracy extremely straightforward! And I think that's what makes Xanadu so interesting. It's trying to do literally everything and spending comical amounts of effort at it, inventing insane things like Enfilades and tumbler numbers[3], all to fall flat on its face with nothing to show for it.
[0] https://en.wikipedia.org/wiki/Folsom_v._Marsh
[1] https://en.wikipedia.org/wiki/Jack_Valenti#Valenti_on_new_te...
[2] Of course, in 1960 NLEs didn't exist. Film (and video) was edited destructively with actual scissors and splices.
[3] I legitimately thought tumblr was named after these things for like years but it turns out, no, it's named after a "tumblelog" which is basically proto-Twitter.
Not to be confused with ATS 3 Xanadu <https://github.com/githwxi/ATS-Xanadu/>
Also not to be confused with the 1980 film starring Olivia Newton-John with a great soundtrack by her, Electric Light Orchestra, The Tubes, and Cliff Richard.