Microsoft Open Sources GW-BASIC from 1983
https://wccftech.com/microsoft-open-sources-gw-basic-from-1983/
Microsoft has announced that after open sourcing MS-DOSÂ two years back, the company is ready to open source some more projects from the days past. Released in 1983, Microsoft BASIC is now open for the public.
The Windows maker said that the GW-BASIC source code being published is from Feb 10, 1983 release. Since that was quite a few decades ago, Microsoft also offered some interesting historical perspective: