What is Mumble?

(Humbly) Copied from http://mumble.sourceforge.net/FAQ/English#What_is_Mumble.3F

What is Mumble?
"Mumble is a voice chat application for groups. While it can be used for any kind of activity, it is primarily intended for gaming. It can be compared to programs like Ventrilo or TeamSpeak. People tend to simplify things, so when they talk about Mumble they either talk about "Mumble" the client application or about "Mumble & Murmur" the whole voice chat application suite."

(We would like to add that it's something like Skype for groups.)

What is Murmur?
"Murmur" is the name of the server application. In any case, if anyone talks about Murmur it is for sure the server part. "

So we will be talking about Mumble: the client application.

Is it save?

Mumble is Free Software, this isn't the same as 'freeware software', so pay attention, no spyware/adware and it's not owned by some big corporation, but it's owned by all of us. To learn more about free software, visit the Free Software Foundation website: http://fsf.org to learn more about Mumble visit the Mumble website: http://mumble.sourceforge.net

And again humbly copied from: http://mumble.sourceforge.net/FAQ/English

"Your whole communication to and from the server is always encrypted. This encryption is mandatory and cannot be disabled. The so-called control channel, which transports your chat messages and other non-time critical information, is encrypted with TLS using 256 bit AES-SHA. The voice channel carrying speech and positional audio is encrypted with OCB-AES 128 bit. You and the server authenticate to each other using digital certificates like they are used for secured connections in Web-browsers."

More information about this can be found at the Mumble website and the Mumble FAQ.