How does the user access the preferences?

1. By hand-editing a file.
2. By using a preferences panel "external" to the app.
3. By changing menu settings inside the app.
4. By using a dialog from within the app.

When do the changes take place?

1. Instantly.
2. After a button click: "apply", "confirm", "ok".
3. After dismissing a dialog: close box, or "dismiss", "close". (these are simultaneous with the above on occasion)
4. After loading a settings/configuration file.
5. After restarting the application.
6. After rebooting the system. (!)

How can the user abort changes?

1. Manually change back. (otherwise known as "they can't"...)
2. Click a "cancel" button. This may mean:
   1. Restore to the state before dialog opened.
   2. Restore to the state immediately following the last "apply" or "confirm".
3. Click a "revert" button. This may mean:
   1. Restore to the state before dialog opened.
   2. Restore to the state immediately following the last "apply" or "confirm".
4. Load a previously saved configuration.
5. Click an "undo" button. This would remove the last change.

How does the user save different configurations?

1. They don't. Only one instance of a configuration is allowed.
2. They duplicate the application.
3. They copy a settings file.
4. They create a new configuration inside the application interface.

How does the user activate a different configuration?

1. They don't. Only one instance of a configuration is allowed.
2. They start a duplicate application.
3. They rename a settings file, then restart the application or perform a settings file reset of some sort.
4. They use an application action to reload the settings from an arbitrary file.
5. They select an existing configuration and activate it within the application interface.
6. They start the application with a command line option specifying an arbitrary file.
7. They open the settings file with the corresponding application. (either by dropping it on the application itself, its deskbar link, or by using a tracker mimetype association.)

How does the user edit the settings when the application is not running?

1. They don't. The settings are only available from within the application.
2. They hand-edit a file.
3. They use an associated application specific preferences app. That is, there is an application whose sole job is to edit the settings for some other application.
4. They use some general purpose preferences editor.

Opinions and comments on issue methods

Since I'm being really lazy and want to sleep, here are my picks: (not in any particular order)

1. Q:How does the user access the preferences?
   A: By using a preferences panel "external" to the app.
   or By using a dialog from within the app.
   and maybe By changing menu settings inside the app.
   usually not By hand-editing a file. (functionality provided as last resort)
2. Q:When do the changes take place?
   A:Instantly. (for any dialog related activity)
   or After loading a settings/configuration file. (for hand-edits)
   After restarting the application (or system) subsumes the prior as well, but it shouldn't ever be required. (if at all possible)
3. Q:How can the user abort changes?
   A:well there's always Manually change back.
   but besides that I favor either
   Click a "revert" button. Which would mean:
   Restore to the state immediately following the last "apply" or "confirm".
   and also Load a previously saved configuration. (at user discretion)
   or maybe Click an "undo" button (or menu option) Which would mean:
   remove the last change
   
4. Q:How does the user save different configurations?
   A:They copy a settings file.
   or They create a new configuration inside the application interface.
   
5. Q:How does the user activate a different configuration? A:They use an application action to reload the settings from an arbitrary file.
   or They select an existing configuration and activate it within the application interface.
   or They rename a settings file, then restart the application. (if they don't want to do any action within the application for example.) It could be possible to activate a new set of settings for an application through the system preferences panel as well but this might be a little bit hairy, and I'm not sure it buys much.
   or They open the settings file with the corresponding application.
   (either by dropping it on the application itself, its deskbar link, or by using a tracker mimetype association.)
   
6. Q:How does the user edit the settings when the application is not running? A:They hand-edit a file. (last resort)
   or They use some general purpose preferences editor.
   

How might all this work? I'm glad you asked. Please take a look at UniversalPreferencesManagement for more discussion.