Joyent is making themselves a cloud player.
Triton: Docker and the “best of all worlds”. Good sense making comment by
_delirium: The main catch (which may also be a plus) is that the Joyent set of technologies is quite opinionated about how to manage a cloud, so you more or less have to "buy in" and do things its way. Your node OS will be SmartOS, nodes will be PXE-booted, your filesystem will be ZFS, the network topology will work in a specific way, etc. More practically, it also takes some time to be proficient in operating it (or even just get it working), because there are quite a few moving parts. Getting a SmartDataCenter deployment running, and then things like Manta and now sdc-docker running on top of it, is more than an afternoon's work. But if you're willing to buy in to the system and its choices fit your needs, it's really well engineered, imo much more "done right" than e.g. OpenStack is.