I think it's fair enough to consider porting a subset of rewriting, in which case there are several successful experiments out there:

- JustHTML [1], which in practice [2] is a port of html5ever [3] to Python.

- justjshtml, which is a port of JustHTML to JavaScript :D [4].

- MiniJinja [5] was recently ported to Go [6].

All three projects have one thing in common: comprehensive test suites which were used to guardrail and guide AI.

References:

1. https://github.com/EmilStenstrom/justhtml

2. https://friendlybit.com/python/writing-justhtml-with-coding-...

3. https://github.com/servo/html5ever

4. https://simonwillison.net/2025/Dec/15/porting-justhtml/

5. https://github.com/mitsuhiko/minijinja

6. https://lucumr.pocoo.org/2026/1/14/minijinja-go-port/

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EmilStenstrom 5 hours ago | parent | next [-]

As the author, it's a stretch to say that JustHTML is a port of html5ever. While you're right that this was part of the initial prompt, the code is very different, which is typically not what counts as "port". Your mileage may wary.

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daxfohl 7 hours ago | parent | prev | next [-]

Interesting, IIUC the transformer architecture / attention mechanism were initially designed for use in the language translation domain. Maybe after peeling back a few layers, that's still all they're really doing.

	▲	nathan_compton 6 hours ago \| parent [-]
		This has long been how I have explained LLMs to non-technical people: text transformation engines. To some extent, many common, tedious, activities basically constitute a transformation of text into one well known form from another (even some kinds of reasoning are this) and so LLMs are very useful. But they just transform text between well known forms.

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MrJohz 3 hours ago | parent | prev [-]

Note that it's not clear that any of the JustHTML ports were actually ports per se, as in the end they all ended up with very different implementations. Instead, it might just be that an LLM generated roughly the same library several different times.

See https://felix.dognebula.com/art/html-parsers-in-portland.htm...