- Source-available software (https://en.wikipedia.org/wiki/Source-available_software)
- Shared source (https://en.wikipedia.org/wiki/Shared_Source_Initiative)
So that it's clear that source code is available in some form, but it's not open source.
I don't think it's a good idea to expand the meaning to cover software that isn't Microsoft's.
I don't think it's a good idea to expand the meaning to cover software that isn't Microsoft's.