### Preferences

> Allows the user to customize the appearance and behavior of the GUI . Please note: some preferences take effect immediately, while others require DS9 to be restarted. Changes to the preferences can be saved by selecting the `Save` button`.` Use the `Clear Preferences` button to restore default settings.

> User preferences files are stored in the directory`$HOME/.ds9`. DO NOT EDIT these files, since it will be deleted or overwritten by DS9.

> Users may have several different preference files. DS9 looks for a preference file with its own name. By default, if the application is named `ds9`, it will look for `.ds9`. However, if the DS9 application is named `foo`, then DS9 will look for `.foo`. In this manner, the user can have several predefined preference files that are activated by invoking DS9 with a different application names.