Cross-platform instant messaging clients with IRC support

There are a number of “unified” instant messaging clients which have IRC protocol support. In virtually all cases, the support offered is good enough to participate in channels, though you may find it lacking if you are trying to manage a channel, and will definately find it lacking if you wish to manage a network.

Pidgin

Pidgin is available for Windows, Linux, and Unix(-like) operating systems. (Adium, an OSX-specific client, is a seperate program, but shares the same internals). Between the built-in protocols, and the protocols available through plugins, the varierty of IM protocol support is extensive, probably the most comprehensive you will find. The IRC support, is very basic though, Pidgin primarily excels at being a Jabber (XMPP) client, rather than an IRC client. However, it’s good enough for most purposes, and if you already have pidgin installed, it might be a good choice for you.

Instantbird

Instantbird is available for Windows, OSX, Linux, and theroretically, for any platform Firefox exists on. It’s built on the same Gecko/xulrunner internals as current builds of Firefox and Thunderbird. Like Pidgin, it’s first and foremost and instant messaging clinet, and this shows in the level of support for IRC, and the user interface. Again, this is going to be good enough to participate in IRC channels, but you’ll find it lacking for anything beyond that.