Cerium

Cerium is an impressive GTK theme that mimics Mac OS X on the GNOME desktop environment. To install this theme, simply right-click on your desktop and select Change Desktop Background. Navigate to the Theme tab and then drag and drop the theme's archive into the Appearance Preferences window. If everything is correctly installed, you'll receive a confirmation message, and you can activate the theme just by clicking on it.

GNOME is an international effort to create a complete desktop environment, including the graphical user interface that sits on top of operating systems using free software. This initiative not only includes choosing application software for the desktop but also crafting software development frameworks and programs to manage application launching, file handling, and window and task management.

GNOME is a part of the GNU Project that can be used on many Unix-like operating systems, most notably Linux, and as part of the Java Desktop System in Solaris. The name originally stood for GNU Network Object Model Environment, though this acronym is now deprecated. The GNOME project focuses on simplicity, usability, and making everything work seamlessly for the user. If you're looking to enhance your GNOME experience, Cerium may be the perfect solution for your desktop environment.