Right, people have certainly implemented hyperlinked versions of code by re-implementing the parser etc. LXR is an excellent example of this. What sets Scribbl

Right, people have certainly implemented hyperlinked versions of code by re-implementing the parser etc. LXR is an excellent example of this. What sets Scribble apart is that * It's a documentation system, not just a code formatter. * It's a programmable documentation system, and the code that _implements_ your documentation is kept appropriately separate from the code that you are documenting. This makes use of Racket's support for phases. * That it doesn't re-implement the parser etc, but can use the built-in one, because of Racket's macros. And, as you say, even if none of this was unique, there's the fact that Racket does it, and has 500k lines of documentation, all done comprehensively in this style.