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. 

If you have g15tools installed and want mumble to use it:
    G15=yes ./mumble.SlackBuild

If you don't want the mumble overlay:
    OVERLAY=no ./mumble.SlackBuild

If your system is x86_64 based, and you have the 32-bit multilib
libraries, mumble will can build the 32-bit overlay
library.

    COMPAT32=yes ./mumble.SlackBuild

Please note, you *must* have a multilibbed system for this to work.
See the mumble documentation on how to use the mumble overlay. 

Celt is no longer maintained, and dropped in is favor of opus.
The bundled Celt is used for optional backware compatibility. To use 
your own try:

    CELT=no ./mumble.SlackBuild
    
Text-to-speech is the default (speechd and espeak). Disable with 

    SPEECHD=no ./mumble.SlackBuild
    
Notes: 
- This does not build the mumble server (murmur).