Volume Icon authors/contributors:

Maato <maato@softwarebakery.com>
 - Developer
 
David Gidwani <david.gidwani@gmail.com>
 - Hotkey support
 
Mihail Szabolcs
 - Notifications

Matthias Frei
 - Show notification only when hotkeys are pressed or when scrolling the icon.
 - Make the volume slider popup downwards if no space is left above the icon.

Jean-Pierre Demailly <demailly@fourier.ujf-grenoble.fr>
 - Option to use a horizontal slider
 - Option to show the numerical value of the sound level on the slider

Matt Boyer
 - Added support for 8-bit OSS sliders and improved configure.ac for OSS