A C++23 hobby TeX engine I've been working on
I was reflecting on some of the recent posts to this subreddit -- the rise of vibe-coded overleaf clones, the crisis of faith post, questions that periodically come up about when and why latex is slow -- and was inspired to share a hobby project I've been working on for a while.
The tl;dr is that I've been working on a new TeX engine, built around the twin ideas of (a) trying to preserve the amazing legacy of TeX (i.e., the engine must be "TeX" in Knuth's sense of passing the trip test) and (b) thinking seriously about the demands of modern document authoring. I think LuaTeX is amazing (I use it every day!), and I simultaneously believe it is worth questioning the boundary between what lives in the macro layer versus what is handled by the engine itself.
To explore this, I've been developing a C++23 version of TeX82 that maintains strict TeX compatibility, while also natively using modern fonts, generating accessible pdfs, outputting directly to html, and doing at least some parts of document compilation in parallel. This engine is not quite ready for release -- out of respect for the existing ecosystem and Knuth's legacy of stability, I want to avoid rushing something out that causes fragmentation -- but I thought it might be a good time to start this kind of conversation.
I'd be interested to hear everyone's thoughts in the comments. I put together a short technical demo showing the parallel compilation and HTML output in action (link).