The EOS M is named as a “beta” supported camera, but you won’t find a download for it in the normal place. Instead, you’ll have to use a “Tragic Lantern” build at tl.bot-fly.com. This forum thread is about the development, while this forum thread includes more how-to and documentation.
Big Huge Labs reminded me that my 10 year Flickr birthday is in just a few days. Tthat has me thinking about the cameras I've used over those years. Ten years is long enough that I had to go looking to remember some, and long enough that I found some I'd forgotten. » about 2900 words