Microsoft Corp has conceded defeat in its instant-messaging spat with rival America Online Inc. The company justifies its retreat on the ground that continuing the fight could expose its users to a security threat. In July 1999, Microsoft released free instant-messaging software that could access AOL Instant Messenger (AIM) buddy lists and interoperate with the AIM system. AOL said Microsoft had no right to release that software. It blocked MSN Messenger from its servers. For months, the companies leapfrogged each others’ software. Every time AOL blocked MSN Messenger, Microsoft would find a new way back into AIM. But version 2.0 of MSN Messenger eliminates interoperability. Director of marketing Yusuf Mehdi says AOL has exposed a serious security bug in AIM and that: To provide an update to MSN Messenger Service that would continue to enable interoperability, Microsoft would need to put our own users at risk in a similar fashion.
