Thanks to NeoWin and WinBeta FYI. Windows Messenger 5 is part of the Greenwich beta released by Microsoft about a week ago. Windows Messenger 5 supports 3 instant messaging services: MSN .NET, Exchange IM (part of Exchange 2000), and RealTime Communication Server (RTC, codename Greenwich). RTC uses an Internet-standard IM protocol called SIP (Session Initation Protocol). This client also supports Ink messages for tablet PC's. Simply install this leaked build on any tablet PC to send Ink messages. For those without a tablet PC, you can still receive Ink messages from your friends with tablet PCs.

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