What does "supports jitsi" mean? Jitsi is an XMPP client, last I checked, are you just saying Matrix supports XMPP?
Re:Jitsi: Open-Source Video Conferencing
by thekelvinliu on Monday January 15, 2018 @11:34PM
(#16155857)
it means there's a first party integration (matrix calls them widgets) with jitsi, enabling video conferencing on matrix platforms.
https://jitsi.org/news/matrix-adds-support-for-video-with-ji...
You probably mean "third party"
https://matrix.org/docs/projects/try-matrix-now.html
https://about.riot.im