IRC commands all start with a "/" (slash). To enter a command, just type it into the bottom of the chat screen.
On IRC, there are channels (the equivalent of "group chat", one that many members can join) and private chats.
You can also chat privately with another member. To start a private chat, go to a channel (e.g. #allfighters), double-click on the member's name in the member list, or enter /query membername.
The advantage of using your own software instead of Mibbit or Java are many:
There are several IRC programs for all major operating systems. If you want to read more, we suggest starting with this WikiPedia article.
I will now describe the usage of a software called Pidgin, because it is available for Windows, Mac OS X, Linux and many other operating systems. The same instructions should work for similar chat software. You can download pidgin free of charge.
(Also, Pidgin can connect you to many popular IM systems like Yahoo, MSN, AOL, etc.)
After you install it and start it for the first time, you will start creating your first connection, called an "Account".
On this screen, simply click on the Add button. You will be taken to the next screen. On this screen, do the following:
Once you're done creating your account, click the "Enabled" check mark that is right next to your account name ("My_Name@irc.meetfighters.com").
Congratulations! You are now connected to MeetFighters Chat with Pidgin!