Domain Whois is a seditio plugin and a excellent addition to host sites. Check availability and see whois information about a domain. It is based on the domain class by Sven Wagener.
The class supports 270 tlds, but only net,com,org,info are enabled if you want to enable or disable some tlds open the plugins\whois\inc\domain.class.php and bettween lines 21-295 comment or uncomment the lines.
Tld or.at disabled org enabled.
//array("or.at","whois.nic.at","nothing found"), array("org","whois.pir.org","NOT FOUND"),
1 : Unpack and upload the files into the folder : /plugins/whois/
2 : Go into the administration panel, then the tab "Plugins", click the name of the new plugin, and at bottom of the plugin properties, select "Install all".
3 : Edit the rights for your groups
4 : Access the plug with the link plug.php?e=whois