Does Slack run on Linux?

Slack makes the Linux version itself. The download page lists three ways to get it: the Snap Store, a .deb installer file for Ubuntu and Mint style systems, and a .rpm file for Fedora style systems. Pick the one that matches your system and it installs like any other app.

Slack calls it Slack for Linux beta. In practice it is the same app with the same messages, channels, calls and file sharing, but the beta label is Slack telling you it gets less attention than the Windows and Mac builds, so the odd rough edge is on you.

Nothing moves when you switch. Your workspaces, messages and files live on Slack's servers, so you sign in and everything is there. If the app ever misbehaves, Slack in a browser is the full product and a reliable fallback.