With apologies to Mickey Peterson, a GPT for yak shavers:
https://chat.openai.com/g/g-ceQ8Ju6Rg-emacs-expert
I used ChatGPT to ingest 10 classic Common Lisp books. The resulting GPT seems even more useful to me than the Hyperspec. In case you're interested:
https://chat.openai.com/g/g-HrUtFVno8-lisp-expert
AI has come a long way baby.