MSN Chat was the Microsoft Network version of IRCX (Internet Relay Chat extensions by Microsoft), which replaced Microsoft Chat, a set of Exchange-based IRCX servers first available in the Microsoft Comic Chat client, although Comic Chat was not required to connect. History Client Compatibility According to the MSN Chat website, the following were required to use the MSN Chat Service: Windows 95 or later Internet Explorer 4.0 or later OR; Netscape Navigator 4.x The Microsoft Network Chat Control was developed as an ActiveX Component Object Model (COM) Object. ActiveX, being a Microsoft technology provided limited compatibility for other products. The other major platforms beside Internet Explorer that MSN Chat was supported on, was Netscape Navigator and MSNTV (formerly known as WebTV). To ensure the MSN Chat network was only being connected to by authorized clients, Microsoft created and implemented a SASL based Security Service Provider authentication package known as GateKeeper. This used a randomized session key to authorize users not using the Microsoft Passport (now Microsoft account) system. Microsoft used another SSP known as GateKeeperPassport, that worked from the same method but required certain attributes related to the user's account. Defeating the "Authentication Challenge" There have been various methods through the use of mIRC to access the MSN Chat Network. Most of the methods were through the use of the MSN Chat Control itself, yet others were more complicated. In the beginning, shortly after the move from Microsoft Chat, the MSN Chat Network could be directly connected to through any IRC Client to irc.msn.com on port 6667. Perhaps because of abuse or other factors, such as the desire to authenticate users based on their Microsoft Passport, Microsoft implemented GateKeeper and GateKeeperPassport, and integrated both into their chat control. The weakness of GateKeeper and the fact the early MSN Chat Controls (1.0−3.0) had public functions for doing GateKeeper authentication seemed to indicate Microsoft wanted third parties to be able to access their network as before, but they wanted to be able to control automated abuse. In any event, these public functions allowed normal IRC clients to authorize themselves. With the release of the MSN Chat Control 4.0, the public functions were removed. Users found a way to authorize by a "Proxy Method", forcing the Chat Control to bridge connections between mIRC and the Chat Network. With the release of the MSN Chat Control 4.2 and later, they blocked this proxy method