Sure. HTML is a Markup-Language (it's in the acronym). Markdown is also a Markup Language. LLMs are super good at Markdown and just about every chatbot frontend now has a renderer built in.

A2UI is a superset, expanding in to more element types. If we're going to have the origin of all our data streams be string-output-generators, this seems like an ok way to go.

I've joined an effort inside Google to work in this exact space, though what we're doing has no plan to become open source, other groups are working on stuff like A2UI and we collaborate with them.

My career previous to this was nearly 20 years of native platform UI programming and things like Flutter, React Native, etc have always really annoyed me. But I've come around this year to accept that as long as LLMs on servers are going to be where the applications of the future live, we need a client-OS agnostic framework like this.