Element
Element is a glossy Matrix client for the web built on top of matrix-react-sdk with an emphasis on performance and usability.
You can use it at https://app.element.io, read more at https://element.io/ and get the source from GitHub!
There is also a desktop version.
Riot Web
Element was previously known as Riot (“riot-web”.) Several packages were made available:
Taw has created RPM package builds for Fedora, CentOS, and Red Hat Enterprise Linux which are available via GitHub and Fedora COPR.
Josué Tille has contributed a Yunohost app.
A Nextcloud app is also available.