I've seen several references to 'Compiz Config' and a 'gnome config' application that seems to not be installed by default. Where do these config applications store their data? Is there a registry similar to Windows or are there just some files that I could edit by hand, if I really, really wanted to?
You can find those in the
Software Center and install them from there.
The 2 first tools will configure different (sometimes not so different, think of it as a path that leads to the same goal) aspects of your Gnome configuration and the last one is important to configure your Unity/Compiz configuration.
gconf-editor stores its data in XML files in
dconf-editor uses files called key files stored in
ccsm stores its data in XML files in your
Any of these can be read and edited with a plain text editor (
gedit, etc.), but it sure is a lot of work. Use the appropriate tools to edit those files, and it will make your life much simpler.
gconf is a rough equivalent, but it's important to understand that Ubuntu and Windows are very different systems. gconf is a "registry" for Gnome, which Ubuntu is now moving away from. It does not control every aspect of the system. Much of the lower-level information is in flat text files spread throughout /etc and /usr/share/name-of-app. User-specific information, including Unity config, is often in dotfiles inside your home directory (that is, files beginning with a ".", so that they are not listed by default. Press Ctrl+H in the file browser to show them).
gconf is equivalent to the registry for many GUI issues relating to Gnome, but holds little sway over Unity-related things.
Many lower level configuration settings are in flat text files in /etc and /usr/share/
Much Unity config is in dotfiles in the home directory.
There is a DBus interface
com.canonical.AppMenu.Registrar that contains the desktop GUI indicator icons and associated ap interfacing details in the Unity environment as described here .