On Thu, 17 Nov 2022, Henning Hraban Ramm via ntg-context wrote:

> Here¢s an interesting example for annotated equations, done with LaTeX/TikZ:
> https://mastodon.social/@sibin/109349703357749846
> 
> I guess something similar is possible with node anchors in ConTeXt/MetaPost?

Yes, this is possible using node anchors and \hpos etc. The interface is slightly cumbersome, mainly because you have to make sure that anchors are unique. 

I sometimes use such constructs in my presentations, but not often enough to build a nice interface as the latex package provides. 

Aditya