GNOME Session Manager - GNOME 3 session
The GNOME Session Manager is in charge of starting the core components
of the GNOME desktop, and applications that should be launched at
login time. It also features a way to save and restore currently
running applications.
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This package contains the required components for the standard GNOME 3
session, based on the GNOME Shell. It can be started from a display
manager such as GDM, and requires 3D acceleration to work properly.