Next Stop, "Greenwich": Enterprise IM Takes Shape with Platform Roadmap "Reeves: Microsoft released the first enterprise instant messaging product as part of Exchange 2000. We were excited by customer feedback, which told us that enterprise instant messaging is an important scenario for Microsoft customers, because it helps information workers get their jobs done more effectively. Two key points came from that feedback: first, make the platform extensible, and also make it usable in more than just the core application. So, we looked at the underlying communications protocol, and moved away from one used only by Exchange instant messaging, toward an industry standard protocol called Session Initiation Protocol (SIP). SIP is approved by the Internet Engineering Task Force (IETF), which shows it already is a communications industry standard. It provides us with a base for presence, as well as the ability to support API's and all of the possible real-time content: text, speech, files, video."