Company (http://www.microsoft.com/ ) headquartered in the state of Washington, in the business of writing software primarily (not exclusively) for use on Intel hardware. OR, as some of us see it, in the business of marketing software (and, increasingly, hardware and services). As some of us see it.
Most well known for a series of operating systems known as Microsoft Windows and an application suite known as Microsoft Office.
Microsoft's applications are known for using communication protocols that are unique to Microsoft. The Wiki has pages on dealing with Microsoft's Component Object Model (COM) and the older Dynamic Data Exchange (DDE) as well as Open DataBase Connectivity (ODBC). Microsoft Excel is also frequently discussed.
For a discussion of .NET and Tcl (and Perl and Python) from the Microsoft perspective, see this article in Microsoft's Technet: "Taking Advantage of Windows 2000 and the .NET Platform" [L1 ]
See also MSH, the Microsoft Command Shell.