Discord is a proprietary platform that offers messaging, voice and video calls, and file sharing. For those with privacy or security concerns there are a couple of open source alternatives.
Fosscord
Fosscord is free, open source, and supports self-hosted servers. It offers many of the same features as Discord such as voice and video messaging. It’s also compatible with Discord so you can still message your friends on that platform. Other features include decentralization, end-to-end encryption, and themes. Customize the platform any which way you’d like to suit your needs.
Revolt
Revolt is currently available as a public beta featuring voice and video chat, messaging, and customization of the user interface. Revolt lets you self-host the app through Docker. Revolt’s platform is available on most modern platforms including Linux, Android, Windows 10/11, and you can use it as a progressive web app.