I had/have an account with DynDNS for years as well, it was much more pleasant than noIP since it did not require to log-in to the account every 30 days or so to prevent it from expiring, and losing the free alias or subdomain.
Finally, about 4-5 years ago I went with a inexpensive shell/web/db hosting provider, which allows to modify the dns records from the shell.
So I wrote an API that allows me to update the dns records via a single web request ( security via a domain_key ) . Since then I basically did not touch it and all the systems that I need to have access to ( family and friends ) register, update their A records on demand, event driven, or after certain period of time.
The service provider is large, located in Poland, provides also VPN, and proxy exits on about 40 different IPs around the world... for a very low price...
They run on FreeBSD, at least on systems that I got access to....
http://www.mydevil.net/en/ ( divide PLN by 3 to get pricing in $$$ )
( I am
not in any way trying to advertise the service - I am just one of their happy customers, who values the FREEDOM of development on Linux )