Microsoft has recently pledged to release the documentation of a lot of its up-to-now internal server protocols.
'Microsoft is providing access through open connections to its high-volume products—Windows Vista (including the .NET Framework), Windows Server 2008, SQL Server 2008, Office 2007, Exchange Server 2007, and Office SharePoint Server 2007—so that software developers, business partners and competitors can better interact with these Microsoft products or invent new solutions for customers.'
Obviously the ones getting the most attention are the server SMB interfaces but also of interest in a real geeky way are ones for the Windows Search Service and WebDAV.
What's tweaked my curiosity is that SharePoint 2007 is mentioned on this list. What interfaces are they talking about? Client side protocols like the FrontPage RPC's? Server side ones? Dunno but it could be interesting.
Personally given the time I spent a long time ago extracting data from a corrupt Microsoft MDB in 2k pages I'd like to see the Jet DB format released, just for old times sake.
Kudo's to Microsoft to releasing this information with a much dignity as anyone with their arm twisted up their back by the EU could.
UPDATE:
thanks to Sean Watson for explaining that the SharePoint related Open Protocols are three WebDAV and two FrontPage ones
MS-WDV Web Distributed Authoring and Versioning (WebDAV) Protocol: Client Extensions
MS-WDVME Web Distributed Authoring and Versioning (WebDAV) Protocol: Microsoft Extensions
MS-WDVRV World Wide Distributed Authoring and Versioning (WebDAV) MS-Author-Via Protocol Specification
MC-FPSEWM FrontPage Server Extensions: Website Management Specification
MS-FPSE FrontPage Server Extensions Remote Protocol Specification
for more details about the Microsoft Communications Protocol Program MCPP and the legal status of these documents see http://www.microsoft.com/about/legal/intellectualproperty/protocols/mcpp.mspx
The gist of it seems to be that open source projects are free to use this information but commercial products would possibly be subject to licencing and patent requirements depending on what they implemented.