When we posted the latest "M" build for CyanogenMod 11, I wondered when the release candidate of the popular custom ROM was coming. It's going to be a while, since apparently they're now a thing of the past. According to the latest CM blog post, that doesn't indicate any real change - they're just moving things around a bit. M builds are now the top tier of CyanogenMod, with nightly builds occupying a lower and more risky level of ROM, followed by pre-alpha "experiments."
Don’t expect a build labelled ‘stable’.