There are gaps in my knowledge, but my understanding is that to address 32-bits of memory requires the use of a "DOS extender". The reason being that DOS is barely an operating system at all- It never provided any 32-bit support but support was possible by monkey patching over part of the operating system in memory. This was possible because DOS had no security measures preventing such horrifying endeavours.

Anyway, I see no reference to a dos extender here so I don't know how it could be anything other than a 16-bit program.

If the author of this framework is looking for a dos extender, I think HX seems like a good choice: http://www.japheth.de/HX.html

unlike other DOS extenders, that provide idiosyncratic apis for allocating 32-bit memory, HX imitates as much as possible standard windows apis, and is able to run some windows applications in plain DOS- including, strangely enough, DOSBox.

(I have nothing to do with HX by the way.)

The compiler used is DJGPP, a port of GCC that comes with a DOS extender, a POSIX-compatible C library and pretty much everything else needed to pretend that you're using a Unix system. Basically Cygwin for DOS.

Yeah, DJGPP is great and I think it was one of the first compilers to work in Protected Mode and take (most of) the DOS/Real mode pain away

Either DJGPP or Watcom with PharLap.

But regardless of who was first (they'll be pretty close, '89 or so) it was a huge step forward for programming on x86. The fact that it was free made it even more amazing.

I think it's the other way around - real mode has the 640kb limit and protected mode gets you a 32-bit address space.