Matrix
/dev/hack operates a Matrix homeserver that acts as a central hub for communication.
Accounts
Matrix allows users on different server to communicate with each other. You don't need a /dev/hack matrix account to use any of our rooms.
If you do not already have a Matrix account and want one from /dev/hack, you will need an IDP account. See the IDP account page for more details on how to get one of those. Once you have an IDP account, you will need a Matrix client. You can use the one at matrix.devhack.net if you're not sure. If you are using a different client, tell it your homeserver is matrix.devhack.net
and you should be prompted to login with your IDP account.
Rooms
There are many rooms, most in a "space". Anyone in the space can see most of the rooms. devhack.net accounts are automatically added to the space and the main room. If you're using a different homeserver, come to #lobby:devhack.net and ask for an invite to the space.