Kurento is not dead. New releases are published from time to time. And its companion project OpenVidu provides a lot of features. Mediasoup and Janus are also really good projects.

Disclaimer: I'm OpenVidu project lead.

Is there a specific reason hindering you from publishing a Debian package, or becoming/appointing a Debian packager, so that your product is available to anyone restricted to official package Debian sources?

Anyone can be a Debian package manager and publish their package in their PPA repository, mediasoup is a Node.js library, think of it as another NPM dependency for your project

Actually Janus does provide a client library. Yeah kurento has kind of ceased to evolve but Janus keeps up with the latest edition of the webrtc standard which continues to evolve and improve.

Janus works pretty well, the endpoints are well documented and allowed me to write a small web app in python for connecting peers through janus. It's not too complicated

mediasoup (in server side) is a Node.js library or a NPM dependency that you integrate into your Node.js app. Of course it comes with tons of C++ lines but, from the point of view of the user, it's just yet another NPM dependency into your Node.js project.

mediasoup overview here: https://mediasoup.org/documentation/overview/

So no documented c++ library to bind other languages through? server side needs to be node.js?

If you want that, probably Janus is something worth looking at.

It's a Node library, yes.

It is more like building block than one off video mettings solution.

Kurento still the easiest to deploy I think. Used in OpenVidu.