They are completely different projects. Jitsi (desktop) was a multi-protocol desktop client whicch supported SIP, XMPP, IRC, etc.
At one point in time it gained the hability to do multi-party video conferencing, where one participant would become the "focus" and forward everyone's video to everyone else.
This was the inception of the concept of an SFU or Selective Forwarding Unit.
Then, in order to scale this up the SFU was extrated to a standalone project: Jitsi Videobridge.
Roughly around then, WebRTC became a thing and Jitsi was already doing many of the required things to bring the experience to the web, so work continued with Jitsi Meet, a WebRTC compatible video conferencing system.
Jitsi Meet is our present and future, but Jitsi (desktop) lives on both as pieces of the puzzle (Jitsi Videobriidge, Jigasi and Jicofo use parts of it) and as a community project, where people interested in keeping it alive ssubmit fixes / improvements.
quick question : is the videobridge a multiplexer -- that is all the clients send the webrtc stream to Videobridge and it combines and forwards the streams to the clients ? Or is it signalling server(STUN) and the clients forward streams to each other ? I am asking this as to decide if I could host the videobridge on on home network (video output from multiple clients would be a problem) or if I have to host this on a cloud ?
I think you have a couple of things mixed up. A stun server is different from a signaling server. Jitsi is an SFU, which is neither. The behavior you describe with combining streams is what we call an MCU. An SFU is simpler and just forwards streams. Most of the logic of an SFU is in controlling RTCP protocols, which are typically aimed at one-to-one use cases. An SFU has to make this work for a one-to-many use case.
At one point in time it gained the hability to do multi-party video conferencing, where one participant would become the "focus" and forward everyone's video to everyone else.
This was the inception of the concept of an SFU or Selective Forwarding Unit.
Then, in order to scale this up the SFU was extrated to a standalone project: Jitsi Videobridge.
Roughly around then, WebRTC became a thing and Jitsi was already doing many of the required things to bring the experience to the web, so work continued with Jitsi Meet, a WebRTC compatible video conferencing system.
Jitsi Meet is our present and future, but Jitsi (desktop) lives on both as pieces of the puzzle (Jitsi Videobriidge, Jigasi and Jicofo use parts of it) and as a community project, where people interested in keeping it alive ssubmit fixes / improvements.