The simple case, if you just want to use it, is that you go to https://riot.im/app https://riot.im/app and sign yourself up as a new user. You can talk to other

The simple case, if you just want to use it, is that you go to https://riot.im/app https://riot.im/app and sign yourself up as a new user. You can talk to other Matrix users, join rooms, and in general use it like any other chat service. Riot is the reference client and you can use it via web, install it as a desktop (electron) app, or install the iOS or Android apps. There are other clients you can use, but for the most part they're all very much in beta. You can also set up some very simple bridging from within the client that will connect a Matrix room to a room in Slack, Gitter, and IRC. It will basically mirror the contents of (say) a Slack room into a Matrix room and vice versa. This process is pretty much just point-and-click. The less-simple case is if you want to do "puppet" bridging, where you can control your own Slack, Discord, iMessage, Hangouts, etc. user via Matrix. The people you talk to using those services won't actually know that you're using Matrix; it just sends messages as if they're coming from your account. To do that, you will need your own server and you'll need to run bridge servers. I didn't find it particularly hard to get Synapse (the reference server) up and running, and I don't have much experience with that kind of thing. The time consuming part for me was just learning how to get a TLS certificate and how to set up a reverse proxy in Apache. Setting up the bridge servers is more of a mixed bag. They're all developed by the community and have differing levels of stability and polish. It will really depend on which ones you want to have set up.