There is Matrix (<a href="https:&#x2F;&#x2F;matrix.org" rel="nofollow">https:&#x2F;&#x2F;matrix.org</a>) - we support messaging and VoIP via WebRTC. Currently we use Freeswitch for conferencing. Check out some clients here: <a href="https:&#x2F;&#x2F;matrix.org&#x2F;docs&#x2F;projects&#x2F;try-matrix-now.html" rel="nofollow">https:&#x2F;&#x2F;matrix.org&#x2F;docs&#x2F;projects&#x2F;try-matrix-now.html</a>