Sailfish could have been great, but Jolla apparently tried to overextend themselves making hardware and software for their products and almost died trying. It's a shame because the Jolla phone had a swappable back part and could have things like a slideout keyboard that looked really sweet. Now they're on the enterprise and government contracting grind and market their OS on their site with all the bs enterprisey jargon, with Sailfish as a community/open-source driven project being mostly an afterthought. They also have a very limited number of devices that can run android compatibility, and you need to pay for a license.

It's a shame because their UI is the only decent thing in the world of Linux phones that isn't an utter travesty that just tries to bend the Linux desktop into being a "mobile OS" that runs like absolute shit and feels really awkward to use. But the UI on Sailfish is of course the proprietary parts aside from the android emulation.