GNOME extensions
also: Shell extensions, GNOME Shell extensions
GNOME extensions are small add-on programs that modify or extend the functionality of the GNOME desktop environment without altering its core code. They can add new features, change UI behavior, or integrate third-party services.
GNOME extensions are optional modules written in JavaScript that run within the GNOME Shell, allowing users to customize their desktop experience. Extensions can modify panels, add applets, change window behavior, or integrate external tools—all without requiring direct changes to GNOME's core source code.
Extensions are managed through the gnome-extensions command-line tool or the GNOME Extensions web interface. For example, you might install an extension that adds a system tray, displays weather data in the top panel, or changes workspace switching behavior. Each extension can be enabled or disabled independently.
Extensions differ from full GNOME themes in that they provide functional changes rather than just visual styling. However, they depend on the installed GNOME version and may break after system updates if not maintained by their developers.