Of course, since AOL files the patent, many other companies have unveiled their own versions, including Yahoo and Microsoft, both of which now infringe AOLs intellectual property.
However, this particular patent become one of the shortest lived in history. Under US patent law, granted patents can be challenged if enough evidence can be presented proving that the concept was already in the public arena before the patent request was presented. And to this end, many prominent technologists have pointed out that MIT has had its own an instant messaging system on campus called Zephyr since the late 1980's, as did Carnegie Mellon University at around the same time.
But the hands down winner was the University of Illinois. Their own online instant messenger was the snappily titled PLATO TERM-talk, and was launched in the mid 1970's, where it was even commercially marketed by CDC, and the original documentation can still be found online at www.platopeople.com / termtalk.html
So far, AOL has declined to comment. But if theirs is any lesson to be learned here, it's that you can often save a great deal of time, money, legal fee's and potential embarrassment with a few minutes of time and a good search service.
