Microsoft released the source code for ' Microsoft BASIC for 6502 Microprocessor - Version 1.1 ' as open source on September 3, 2025. While the 6502 BASIC source code had previously been distributed ...
Microsoft released the source code for MS-DOS versions 1.25 and 2.0 through the Computer History Museum in March 2014. This was also intended as a historical document summarizing 'how MS-DOS was born.
The development tool for rapid prototyping of XAML code is now available as open source. It is on its way to version 2.0 with some new features.