Our server is called "Duion.com - Free Public Server" and the adress is also "duion.com" like this site.
We use Mumble for most communication and as a community meeting point.
For this we have our own server, which is free to use for anyone, so if you need some free slots for your clan or else and don't want to rent your own server, you can just use this one.
On the links underneath or in the menu on the left, you can find basic guidelines how to get started with mumble and instructions how to use our server, if it should be necessary.