Wed Jun 12 13:57:31 EDT 2013
What target to pick?
+ combined with PIC18 support in Staapl, I could aim at 1 vendor
(Microchip) / 1 tool (Racket) approach.
+ DIP available, good for grassroots electronics projects
- typical quirky DSP arch with lots of constraints
- no free optimizing C compiler for both PIC18 and dsPIC.
ARM Cortex M4 
+ industry standard, multiple vendors: TI Stellaris, STM32 F3,F4
+ good open tooling support
+ plenty of boards
- no DIP available