Different operating systems have differing features, though they all have the primary function of controlling the software and programs running on a computer or other device. Popular features include: A start menu or application menu (Windows, Linux) Multiple desktop workspaces (Linux, Mac OS X) Taskbar (Windows, Linux) or dock (Mac OS X, also Linux) to track favorite program shortcuts and active applications A desktop environment. Linux has GNOME or KDE (and a few others), Mac has Aqua, and Windows Vista has Aero. Desktop acceleration (Mac OS X, Linux using Compiz or similar, and Windows Vista Premium, Business, or Ultimate)