Serverlist

The Whois Serverlist is also available as an XML file (http://serverlist.domaininformation.de/). A human readable Whois Serverlist is also available.
If you want to use the XML file automatically (for example for your own Whois Service), then please keep the following points in mind:

In order to save resources use "HTTP-Compression".
The list tries to be up to date, but you should only request it once per day.
Use a caching mechanism.
In order to check if your version is still up to date, you should use the Last-Modified Header.
So it's not necessary to download the complete document.
The DTD of the serverlist may change. So your applications can break. Any changes will be announced at News.
To avoid surprises you can subscribe to the Newsletter.

XML Whois Serverlist