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 are stored in $HOME/.ds9.prf. DO NOT EDIT this file, since it will be deleted or overwritten by DS9. The file permissions must be group/world readonly.

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.prf. However, if the DS9 application is named foo, then DS9 will look for .foo.prf. In this manner, the user can have several predefined preference files that are activated by invoking DS9 with a different application names.