Xchat is an application that is simple and will work on Windows and Linux. While Xchat is open-source, the Windows version does have a charge for use, it has a free 30 day trial period though. But, you can download and use Xchat2 for Windows which is a version of Xchat for windows that simply uses the source code and then runs it for Windows, but does not utilize Aero and other features that the official version does.
We will be showing you how to setup Xchat using the free binary from Silverex. If you are using Linux then you can install it simply by getting it from your repository, it is in almost every one by default.
So if you are on Windows, head over to Xchat from Silverex and get the binary. From there install it just like any other program. You should probably uncheck all the scripting languages during install since they aren't really needed.
When you first launch Xchat you are going to be presented with some default options and a list of built in IRC channel connections. All you need to worry about here is changing your default nicknames. You should use a unique nickname and keep in mind that if one is already registered, your nick will be changed by the IRC network. Once you change the default information find “ Freenode ” in the network list.
Once you find Freenode, click on “Edit” to the right. All you need to do here is add “#category5” into the Favorite Channels list. If you want to have it autoconnect you can simply check that box and then not worry about clicking Join anymore to get to the chatroom.
You are now ready to chat in the room! WooHoo! Just don't flood the place, because that would be bad.