Microsoft today announced that it is open sourcing GW-BASIC. In 1983, Microsoft released GW-BASIC for the IBM PC XT and compatibles. GW-BASIC is a BASIC interpreter derived from IBM’s Advanced BASIC/BASICA (a port of Microsoft BASIC)

You can check out the source code of Microsoft GW-BASIC on GitHub today. The source code of GW-BASIC is written in assembly language.

Here’s why Microsoft is open sourcing GW-Basic:

These sources, as clearly stated in the repo’s readme, are the 8088 assembly language sources from 10th Feb 1983, and are being open-sourced for historical reference and educational purposes. This means we will not be accepting PRs that modify the source in any way.

You can learn more about this announcement from the link below. Back in 2014, Microsoft open sourced MS-DOS as part of a collaboration with the Computer History Museum. In 2018, Microsoft re-open-sourced MS-DOS on GitHub. The new repo contains the original source-code and compiled binaries for MS-DOS 1.25 and MS-DOS 2.0.

Source: Microsoft