Arduino Due is another Arduino board, but with Atmel ARM processor instead of AVR. I have had Due for a while, but flashing it on Linux had not been working. However, now I managed to flash simple blink app (written in C++) on Linux using bossac:
sudo ~/programs64/arduino-1.5.1/hardware/tools/bossac --port=ttyACM1 \ -U false -e -w -v -b /tmp/build5203148458475074262.tmp/Blink.cpp.bin -R
This means that I can start porting GNAT and a variant of AVR-Ada to Arduino DUE. All of the AVR packages need to be rewritten and other packages will need quite big changes also, so don't hold your breath. If I am lucky, I have something ready before end of the year. :)
Ps. Before running bossac, you need to hold erase button down for a few seconds.