[](https://movq.de/v/d4be7212d2/dusage%2Dboth.png)
This compatibility layer only applies to 16 bit OS/2 1.x programs:
https://en.wikipedia.org/wiki/Architecture_of_Windows_NT#OS/2_environment_subsystem
32 bit OS/2 2.x programs don’t run:
[](https://movq.de/v/d4be7212d2/dusage%2Dos2v2%2Don%2D2k.png)
I wonder how many text mode 16 bit OS/2 programs still existed when Windows 2000 came out. 🤔 Was it really worth keeping this subsystem around for so long?