XDG-Prefs

XDG-Prefs is an Open-Source tool to manage your default applications on GNU/Linux, with a simple but efficient GUI.

On GNU/Linux systems, each file has a type, named the MIME Type (or Media Type), based on the XDG Specifications by Freedesktop. Your system maintains a database that specifies the default application you want to use for each MIME Type ; this database is available through the official xdg-mime tool, but the command-line interface is not suited for easy management (for example, you must remember the exact name of the MIME Type).

XDG-Prefs offers a simple GUI that allows you to view and modify this database easily; it is built upon the same standard specifications, meaning that your preferences will be recognized by all other applications (typically, when you double-click on a file in your File Explorer).

Such a tool is commonly found in Desktop Environments, such as Gnome or KDE, but not in Window Managers, such as i3wm. XDG-Prefs is desktop-agnostic, meaning that you can use it on Gnome, KDE, or even i3.