I know it has bee posted before, but it seems to get overlooked. Joomla! really has not good chat programs, and this is the best, most customizable program that I have seen. Please, someone, make a Joomla! phpFreeChat bridge.
I tried FreeChat! and do not recommand this component: basically it loads PhPFreeChat in an IFrame. You can perfectly use PHPFreeChat "as-is" in Joomla!, which has many advantages over the FreeChat! component: always have the latest version and great support; being able to put the chat in content, so you can really integrate it; FreeChat! hides the commands section by setting "scrolling" to "no" in the Iframe (you can change this of course, but you'll have extra scrolling bars); Iframes display differently in IE than in Firefox (IE puts white margins around the framed pages); you cannot avoid people to reach the framed page directly by url, thus bypassing eventual user restrictions you had set up (for instance "registered users only"...
If you don't know how to make it work, I'll post a template code here.