Windows Home Server (Cancelled 1997 version)

Windows Home Server (Not to be confused with the 2009 release of the same name) was an ambitious project to make a version of Windows NT 4.0 for those who want "stay at home servers" with User Friendly features, but due to development problems (and the team wanting to work full time on Windows NT 5.0 and Windows 98), it was cancelled in 1997.

Source code release
Microsoft released the source code to the Windows Home Server kernel in 2005, the move was met with some conterservey due to the OS essintally being a modified Windows NT 4.0, witch had its kernel source code leaked the year before. Non the less Microsoft hoped that users can use the Windows Home Server source code in many ways they coulden't do back in 1996.