[Panzerschrek]

It's surprise for me that there are still non-opensourced MS-DOS versions. Why keeping them closed?

And I see no reason not to opensource early Windows versions (up to 2000).

[olivierestsage]

If win2000 got updated by the community with improved driver support people might actually prefer it to current Windows, which would be humiliating.

[rbanffy]

ReactOS is a better Windows 2000 than Windows 11 will ever be.

[rep_lodsb]

Last I checked, it's still mostly unusable, especially on real hardware (both modern and Win2k-era). Not saying this because I have anything against it, that's just a fact.

Of course one could say that Windows 11 provides negative value, in which case running DOS 1.00 would also be better ;)

[rbanffy]

The main issue for open-sourcing old software is copyright. Not all companies buy the copyright of the tools and libraries they incorporate in their software, making it difficult, if not impossible, to open source them.

Also, getting the source code for external libraries was not common until open source became the norm. Making something open-source often requires rewriting parts of it.