Preserving code that shaped generations: Zork I, II, and III go Open Source
Microsoft’s Open Source Programs Office (OSPO), Team Xbox, and Activision are making Zork I, Zork II, and Zork III available under the MIT License.
Scott Hanselman articles
Bringing BASIC back: Microsoft’s 6502 BASIC is now Open Source
For decades, fragments and unofficial copies of Microsoft’s 6502 BASIC have circulated online, mirrored on retrocomputing sites, and preserved in museum archives. Coders have studied the code, rebuilt it, and even run it in modern systems. Today, for the first time, we're officially releasing it under an open-source license.
Open sourcing MS-DOS 4.0
In partnership with IBM, we’re releasing the source code to MS-DOS 4.00 under the MIT license to support open innovation.