My presentation at the EmacsConf2023 was titled "REPLs in strange places: Lua, LaTeX, LPeg, LPegRex, TikZ". Due to personal problems I had to present it in a very incomplete form, and it ended up being mainly about the design decisions behind some Lua programs - or "modules", or "libraries" - that were not finished at the time of the conference.
All those programs are built on top of two modules: Show2.lua and ELpeg1.lua. After the conference I wrote this sandboxed tutorial - (find-show2-intro) - with executable instructions for installing this version of the modules and testing most of their main parts.
Note that at some point I will create versions of Show2 and ELpeg1 that will be incompatible with the current ones, and that will have names like Show3, Show4, ELpeg2, ELpeg3, etc - and the repository with these other versions will have other names that are not "show2-elpeg1".