Another option is the Linode DNS Manager. They also have a pretty decent (as far as I can tell, never used it, have my own solution) API for managing them. Or y

Another option is the Linode DNS Manager. They also have a pretty decent (as far as I can tell, never used it, have my own solution) API for managing them. Or you can just do it via the website. As far as I can tell it's free of charge, as you only need to be a member, but since I host two of my external DNS servers there I cannot actually check that you don't have to be a customer. Maybe a fellow HN user can verify? On another note, hosting DNS is really easy once you get the grip on how things work.