I love the idea! I could imagine something similar created for other languages too. Perhaps written in a way that a template could be reused in, let's say Django, and a JS React frontend. With all the type-safety that tsx provides.

I recently built some templating language (rather an intermediary language for documents) for solving an accumulated frustration over the years. Already added into four or five of my projects (for templating html, emails, dashboards, chatbots messages, and some configs).

The design point "deterministic, hostable, with enough to make hooks from the templates" is what makes it special: https://lucasdicioccio.github.io/tramaj/ .

I always thought that the type-safe XML/HTML in Ur/Web was elegant.

For examples, see http://www.impredicative.com/ur/demo/

There was a brief period where everyone and their dog implemented mustache[0] as a template system, but it died quickly because cross-language templating is not that useful in the end, you seldom need to switch host language but keep the templates.

0: https://en.wikipedia.org/wiki/Mustache_(template_system)

Type safe DSLs in Kotlin

https://kotlinlang.org/docs/type-safe-builders.html

This is sort of halfway between tsx and Elixir's EEx

I think nim also has this.

As for Django... well.. Django only has text formatting, you can write any garbage and broken html and lots of invalid templates with silent failures there unfortunately.