MercuryOS jumped out at me too, digging around the site I really started to imagine using it. It does not appear to have gone beyond the design (which was where the creators intended to stop it seems). It's a re-imagining of HCI than an OS as a whole. It caught a fair bit of unfair flack previously imo: https://news.ycombinator.com/item?id=35777804
rbanffy|9 months ago