Microsoft might have killed off its Messenger service in favor of Skype recently, but back in 1999 it was the centerpiece of a heated war between the software giant and AOL. At the time, Microsoft had just introduced its MSN Messenger Service as a direct rival to AOLs popular AIM instant messenger. David Auerbach, a former Microsoft engineer who worked directly on MSN Messenger, recounts his unusual role in a chat war with AOL. Auerbach had reverse-engineered AOLs chat protocol to allow MSN Messenger to sign into AIM, a process that AOL wasnt happy with when Microsoft first released its instant messaging client in July 1999.