Hi,
I pushed the first version of a dynamic DNS client for IPFire, yesterday:
http://git.ipfire.org/?p=oddments/ddns.git;a=summary git://git.ipfire.org/oddments/ddns.git
It is written entirely in Python and offers a class modem for the providers. Every provider gets an own class which updates the specified account. The configuration file syntax is unified and extensible, to support an easy way to add new accounts have the option to add some more configuration variables when needed.
A lot of important stuff is already done like support for an upstream proxy server, a generic provider class and a basic command line tool. There are currently two providers supported: No-IP.com and selfhost.de
IMPORTANT: I am not planning to add any more providers by myself. But I think there might be interest in having more providers and some more features, so this is an open request for a new maintainer of the tool.
If you are a Python programmer and have interest in maintaining this little piece of software, write new features and fix bugs, please mail me.
Michael
P.S. I will eventually add some licensing information which is missing for now.