Prior art against the instant messaging patent

by Matthew Gast

As many others have noted, U.S. patent 6,449,344 was issued to AOL last September. Naturally, many people have said that the patent is "obvious," and have started to search for prior art. Tim O'Reilly received an e-mail noting a possible previous communication system, but the legal system is heavily weighted in favor of printed and dated pieces of paper. E-mails and screen captures are not likely to be effective prior art in litigation.

Greg Aharonian's PATNEWS mailing list is a fun-filled newsletter, always delivered with at least a slight touch of sarcasm. (Sign up for the list here.) A recent message noted two papers that might undermine AOL's newly minted patent. Both describe Zephyr, a communication system developed by MIT as part of Project Athena.

  • DellaFera, C.A., et. al. "The Zephyr notification service." USENIX Association Winter 1988 Conference, pp. 213-219. (Sadly, USENIX conference proceedings are only on-line from 1993 onward, so this paper isn't available in electronic form.) The abstract reads:

    "Zephyr is a notice transport and delivery system under development at Project Athena. Zephyr is for use by network-based services and applications with a need for immediate, reliable and rapid communication with their clients. Zephyr meets the high-throughput, high fan-out communications requirements of large-scale workstation environments. It is designed as a suite of 'layered services' based on a reliable, authenticated notice protocol. Multiple, redundant Zephyr servers provide basic routing, queueing, and dispatching services to clients that communicate via the Zephyr Client Library. More advanced communication services are built upon this base."

  • Fay, D.Q.M. "Internet and the electronic classroom." Microprocessing & Microprogramming, December 1994, pp. 847-50. The abstract reads, in part,

    "Describes the use of gopher, WWW, ftp, telnet, e-mail, and online Zephyr messaging for a first-year university undergraduate computer science module. The aims of the module, and the profile of the students are described. The computing environment available to undergraduates is described in detail..."

Also, Jabber has their own analysis of the technology claimed by the patent. Their analysis draws from a basic interpretation of the patent by a patent attorney.

I've never used Zephyr. If you have, how much like IM was it?


2003-01-10 05:59:49
So I'm curious as to where PowWow fits into all this. I think it used to be available at, but seems to be gone now. I used PowWow as my IM client in 1995-96, prior to finding ICQ, and it had been around for a few years then. I scanned the patent but could't tell how far back prior art needs to be.
2003-01-10 09:35:46
Required prior art date
Prior art needs to pre-date the invention. Without having examined the file, my initial assumption is that instant messaging was "invented" on the date the patent was filed. (January 27, 1997). Anything which pre-dates that is worth considering as prior art, though of course, farther back is better.
2003-07-31 07:24:54
prior art in 1965
MIT's CTSS system had "interconsole messaging"
which allowed text messages between users.
One could check if a user was logged in with the
WHO command, and send messages using a feature
of "." ("dot"), the command abbreviation program.
Messages were sent to the user, regardless of
what terminal logged in from.

Similar facilities were implemented in Multics in the early 1970s, including a command called "check_logged_in" that could periodically check if any of a list of users were loggged in, and the "send_message" command which sent messages.