"Chat with your AIM, ICQ, Yahoo Messenger and IRC contacts"
Trillian is an excellent alternative to talk to all your acquaintances for free.
This instant messaging program works really well, being able to start audio and video chats with excellent performance. In addition, you can chat by these means with a multitude of people at the same time, without having to opt for additional programs.
To use Trillian you must create an account. After logging into the program you can proceed to add all your contacts, which must also have their own program account
Trillian's interface fails to be as intuitive as it should be, although once you get used to the menus they become very comfortable as well as functional.