This is asoundconf-gtk, the GTK+ applet to allow you to select your default sound card. It is licenced under the GPLv2, which you can find in COPYING, and is (C) 2006 Toby Smithe. The projects which code has been taken from are also subject to copyright, and this is further detailed in the source file. It is Python, so you can execute it from source, which is found in asoundconf-gtk/asoundconf-gtk, but you can install it as well, using setup.py. This places the .desktop file in /usr/share/applications as well, which on a GNOME system should place an icon in System->Preferences.