I now have a beta version of ARM uLisp that works on the Adafruit Feather STM32F405 Express.
uLisp runs OK, and it seems very fast; for example, (tak 18 12 6) gives a time of 2.9 secs. However, the Arduino core serial port implementation seems pretty broken, and I can’t upload anything more than a few lines of Lisp without getting dropped characters.
If anyone has a board and would be interested in helping to get uLisp to work well on that platform please get in touch, and I’ll get you a copy of the beta.