Currently the title says "Web-based IBM 1620 emulator and IPL-V from 1963" until HN's title policy inevitably vandalizes it to remove the informative part. But, to give further context on IPL-V, IPL (I think actually IPL-IV) was key to some early AI research, but the main reason it's interesting in 02026 is that it's what inspired Lisp. It's a terrible programming language by today's standards, and the manual is a horrible slog, but you can see the seed of almost every programming language popular today in it.