Is there a way to allow people to set up and use .ssu.lt

Assuming ssu.lt is your domain, see the domain.resource.* commands at https://www.linode.com/api/. Just add a frontend in the language of your choice.

Thanks for showing me that. Do you know how I would use that for people to create and control their own domain names? I could possibly make a simple PHP and MySQL web application for keeping track of user accounts that would have some sort of interface with the API for managing domains.

Several months ago I was looking into doing a dynamic DNS-type service using the Linode API, and could not find any existing suitable web front end. I concluded I would have to write my own. I never got around to doing it, so unfortunately I don't have anything to share with you.

You could perhaps do it within MediaWiki by writing an extension to manage it; at a minimum I think you would need to create a new database table to store the information. You could use the (unofficial) PHP bindings for the Linode API to add/remove/change subdomains.

Some sort of management interface is going to be important. You'd also need to have the domain names divided up to the owners of them and provide a way to manage A, CNAME, MX, and TXT. It might be easier on my end just to write a new application, because I've had stupid problems trying to figure out how to add content to special pages in MediaWiki.

I've made a domain look up for it, which could be connected to by such a web application for users to add contact information for their domains. I've heard something about making your own whois server the way you can make a nameserver, which might be preferable to just a web database. I can also hide various fields for the contact information; I might leave out the entire billing section since it's not needed for a free domain name.

http://www.whois.ssu.lt/

One thing that I might add to the application would be a way to approve accounts before they can register domains after they give a reason so that I can prevent spam on a free service and keep it to domains for Warhammer 40,000 websites.

I just made a project on GitHub for anyone who has any interest in working on it.

https://github.com/Sturmkrieg/LinodeDomainRegistrar

Cool. If I pick up my project again I'll definitely look at your code and see if I can contribute.