I now have a compiled build under Open Watcom running FreeRTOS in 32 bits, using Fastgraph for DOS under the Causeway stub, with FastGUI as the foundation for the interface, with SQLLite and WATT-CP as the network library. The prototype is looking good. The build is 700K+ but the virtual memory manager under Causeway is quite capable of running overlays into the available RAM for huge programs. So once the stub loads, your program can be very huge and loaded in pages on demand. I've used the Causeway overlay manager previously and it was incredible given it's tiny size.
Screenshots soon. Beautiful desktop coming along with very unusual looking interface theme and appearance. Scrolling ticker at bottom runs nonstop in addition to floating terminal console.
I'm planning to put everything into RAM so if necessary the program can run off a single compact flash card plugged into a terminal with otherwise no hard drive storage or other peripherals. Even SQLLite can keep the database in RAM completely until it is flushed back out to compact flash. I want to support monochrome and have been working on GUI widgets drawn entirely by program logic instead of themes using bitmaps. My inspiration is coming from this kind of design, something completely different from traditional Windows and Linux interface looks.