You can replace DOS extenders to a certain extent. DPMI is standardized, so if an application is directly developed against the DPMI interface, it doesn't matte

You can replace DOS extenders to a certain extent. DPMI is standardized, so if an application is directly developed against the DPMI interface, it doesn't matter which DPMI server is present. I remember that some programs would run without any additional executable on Windows 98 (which provides its own DPMI server) but would require CWSDPMI.EXE when run from DOS. I guess that other programs would directly communicate with DOS/4GW through a different interface and that's when you can't just replace it with a different extender, but there are other extenders that can fully replace DOS/4GW such as DOS/32.