I use <a href="http://www.rackspace.com/cloud/dns/" rel="nofollow">http://www.rackspace.com/cloud/dns/</a>
Free RESTful API with language bindings.<p>Api docs: <a href="http://docs.rackspace.com/cdns/api/v1.0/cdns-devguide/content/index.html" rel="nofollow">http://docs.rackspace.com/cdns/api/v1.0/cdns-devguide/conten...</a><p>Python examples: <a href="https://github.com/rackspace/pyrax/tree/master/samples/cloud_dns" rel="nofollow">https://github.com/rackspace/pyrax/tree/master/samples/cloud...</a>