NEW: 9 videos (86min) about CLOS on my Common Lisp course. Out of 7h+ of content. Rated 4.7/5. Learn more and stay tuned. 🎥 I also have cool Lisp showcases on Youtube . The last ones: how to build a web app in Common Lisp, part 1 and 2. Hacker News was written in the Arc lisp dialect, a dialect created by Paul Graham. Arc was implemented on top of Racket, but that has now changed. HN runs on top