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.