I don't know if this issue has already been addressed or not, but when I put the www. before the url of a website that is hosted by xepher, it just goes to the main page of xepher.net.
I've tried it with multiple sites, and they all have the same problem. It works fine when you don't put the www. in front of the url, though.
???
The short answer is: it's intentional. I prefer it as it keeps URLs shorter, and I don't like typing extra "W"s for no reason.
The long version is because "www." is not part of the site name. The "www." subdomain started being used because back in the dawn of the web, many large companies and organizations need to run the webserver on a different address/machine than other services like ftp or telnet, and there was only one website for the whole company or university. Here though, there's lots of sites, so we use subdomains to separate different user sites... so the webserver can read the first part of the server name, and know whose site it should go to. When you put an unknown (or, more commonly, expired/deleted) username in there, the webserver redirects to xepher.net itself. Most websites do that for unknown pages. Since it doesn't know any user called "www.username" it redirects. You can try any gibberish in front of xepher.net and it'll do the same thing. http://pekdhdkawimvo.xepher.net/ , for example, will go to the front page as well.
Alternatively you could change your DNS setting to point all sub-domains, including the www one, to a cname of your primary domain. This would accomplish the task you are aiming for.
The DNS already does, that's why all subdomains end up on the main page by default. It's the apache config that would have to be changed. I know I could set it up that way, but I don't want the extra Ws, it just makes things more complex than they need to be. Keep in mind, this is only for the username.xepher.net URLs, not when people have their own domain name. Those support the www still.
That's only true if they are hosting their DNS through Xepher for their domain name (I wasn't referring to the *.xepher.net domains).
Like with my domain I host my DNS records elsewhere, so I'm able to define specific details on what points to what. I noticed the thing with the www sub-domain going to the main xepher page so change that to a cname record instead of an a record. It also allows me to point the other sub-domains to other servers (like I do with the images and guides sub-domains).
Ah well... the complaint above was specifically for the *.xepher.net subdomains I think, since as I said, the virtual domains do support the www, and all work. Also, I do host DNS for all domains hosted here (with a couple of exceptions) specifically so that I can make sure stuff like that works as expected. Most people that want a domain for their website on a free hosti (like this) usually don't know or care enough to understand things like MX and CNAME records, so I just run the DNS as well. It's actually wildcarded so *.userdomain.com goes to their site in that case.