FORTH OLIMEXINO-STM32 !
Another interesting development board is the Olimexino STM32. It is compatible to the LeafLabs Maple, using a Wiring based library and simple IDE (very similar to the Arduino boards). I couldn't resist and had to bootstrap CoreForth on this board as well :)
Granted, this was a bit easier since I have CoreForth already running on another close relative (the STM32-P103, also from Olimex), so it just took a couple of hours to get the basic interpreter and compiler loop running. On the ARM SoCs it really just comes down to initializing the clocks, the GPIOs and the UART - afterwards, it's all native Forth!
Regarding the Arduino Due, I got the interface to the embedded flash controller working, and can now enjoy a very retro block editor with the ability to preserve all work over reboots. It's almost a full blown development system, just an ARM assembler for Forth is missing.