Foldit's in-game chat is based on IRC ("Internet Relay Chat"). Anyone may connect to the Foldit IRC server either through the Foldit game client or through external IRC clients.
Foldit also uses IRC internally for things like downloading recipes and puzzles via the fold.it website. For example, the "Add to Cookbook!" button for a recipe on fold.it uses IRC to send the recipe to your fold.it client. You must be logged in to the fold.it website and have an IRC-connected Foldit client running for this to work.
As at December 2014, the Foldit IRC system hides user IP addresses from connected users and Ops.
Turn off in Game Chat You can block non-group chat: Click "Menu" and then click "General Options", a menu appears where you can check and "Disable non-group chat", this will take effect when you next restart Foldit.
Multiple clients Players can run multiple Foldit game clients at the same time. Only one client, however, can be connected to IRC chat. The other clients are disconnected from IRC and can't chat. The disconnected clients also won't receive recipes sent via the "Add to Cookbook!" button.
Foldit IRC server and channels
Foldit's IRC server is irc.fold.it, port 6667.
The #global channel is available to all players.
The #veteran channel is available to players with a minimum level of experience. (It's a fairly low minimum.)
Players who join a group have access to that group's IRC channel.
The #global channel is open to all, but the other channels, particularly group channels, require an IRC key.
The IRC key can be found on a player's "My Page".
The IRC key is used on a "/msg NickServ IDENTIFY *irckey*" command, where *irckey* is the IRC key from the fold.it web site. Many external chat clients can be configured to send this command automatically when connecting to irc.fold.it.
External IRC Chat
Although the Foldit in-game chat is sufficient for many players, some players prefer to access chat using an external client. Using an external client can allow for chat access on a second computer. External clients offer options which may be helpful for those with vision problems. External clients also offer the ability to click all links, the ability to copy/paste, and the logging of chats.
Normally, users create a second Foldit user id for use with the external chat client. This user id should only be used for external chat, never for logging in to a client and folding. See this description of how to create a Foldit IRC account for details. The IRC key for the second Foldit user id is used to configure the external IRC client.
The alternative to creating a second Foldit user id involves making sure that all Foldit clients are closed. Once the clients are closed, the existing Foldit user id can be used to log in with the external chat client. Most players find that having a second Foldit id to external chat is easier to deal with.
Players who belong to groups with controlled access should ask for the second Foldit user id to be added to the group as well.
Players can use install an IRC program such as IceChat for PCs or Colloquy for Macs to access external chat.
Alternately, players can use a web-based IRC client, such as Mibbit.
Troubleshooting for group chat
Players have encountered intermittent problems with accessing group chat. There's a "Fix IRC Group Chat Permissions" option on the fold.it web site which may correct some of these problems. Make sure that you're all Foldit client and external IRC clients are disconnected from the Foldit IRC server. Go to the fix IRC option, click the checkbox, and click "Save". This option is reputed to be most effective if applied shortly before the hour, for example at 9:55 or 21:55. It's not clear whether there's any technical merit to this idea, however.
The IRC Group Chat Permissions section of the IceChat setup instructions also discusses this topic.
External IRC for Group Chat (special instructions for Group Admins)
The Foldit IRC server uses group membership on the fold.it website to determine who can access a group chat room. When a player wishes to use an external IRC client with an IRC-only user id, they just need to join the Foldit group with that user id. If someone not in the group tries to access a group room they will be kicked (not banned). This eliminates the old problem of players getting banned from the group room when they accessed it from a different IP address or when their IRC client attempted to auto-join the group room prior to authentication.
Anyone who is listed as a group admin on the fold.it website will also have ops privileges in the group chat room. It is no longer necessary to give chat ops privilege to everyone using external IRC, since the banning problem has been removed. Anyone who should have the privilege to kick or ban people from the group IRC channel can be made a group admin on the fold.it site.