I have used http://freedns.afraid.org/ and I like it.
Nowadays, I don't use it as often, mainly because I'm having little time to set up network services and such. If you make a public server, please contact us. I think the FSF lists service providers which use and deliver free software (remember that OwnCloud is free software? So its default JavaScript is *probably* free too, although we must still insist on the correct GNU LibreJS markup).
