http://www.mirc.co.uk

It is a free chat program. The thing about it is that unlike ICQ, MIRC works through several different networks of servers that operate independently of each other.

To log on to a specific chat group, you must be in the right network first. The Dominican groups I have talked in are through Undernet.

IRC is not difficult to use, but it is not particularly intuitive either, so you will have to read the instructions. There is lots of help available through their websites and included with the program, which you download.