Command line to Yahoo Instant Messaging

I need an application that can send Instant Messages to Yahoo. The application must can be written in anything that can run on linux, with as little dependencies as possible (for compatibility issues). The application must be at all times connected to Yahoo, because if we use it too often and it logs in each time, the ip/account might be banned from yahoo and I certainly do not want that. The overview of the application that I've thought of is like this. This should open a local port and accept connections from all IPs (I will handle the IP white/blacklisting from the firewall, so you don't bother about that). The protocol used to communicate should be faily simple. XML is a very good choise. In return the application should return an errormessage, with the result of the attempt of sending the message (also XML format for consistency).