Before I get into the actual topic of this post, a plea. Please reference results in the stacks project by their tags (which are stable over time) and not in any other way. The tags system is explained here and here and latex instructions can be found here.
Just today I changed the output of the result returned if you lookup tags. See this sample output. You’ll see that currently the result of looking up a tag gives you to corresponding latex code. Moreover, cross references in the proofs and statements are now hyperlinks to the corresponding lookup page. This means that you can quickly follow all the references in proofs of lemmas etc down to the simplest possible lemmas.
Of course this isn’t perfect. In many cases the lemmas need more context and you’ll have to open the pdf to read more. Another complaint is that it is cumbersome to have to parse the latex. I think having the latex code available for quick inspection is good in that people can edit locally and send their changes here. In the future I expect to have a variant page where the latex code is parsed (ideally something like a png file with embedded links for cross references). A requirement is that lookup is fast! (Lookup is already not instantaneous, but I’m sure that is due to poor coding skills of yours truly. I’m not convinced mathjax or anything like it is the answer: I don’t like the way it looks and I don’t like how long it takes to load.)
Please let me know suggestions, bugs (things that don’t work), etc.