GNOME is a community-driven open-source project for desktop environment for GNU/Linux. The GNOME community is also involved in contributing a wide range of core applications that run on GNOME desktop.
Check If You Are Running GNOME Desktop
To verify that you are using GNOME desktop, run the following command:
$ ps aux | grep gnome-session
If the above command displays gnome-session process, it means that you are using GNOME Desktop.
If you would like to determine the version of GNOME desktop you are using, use either of the two methods described below.
Method One
gnome-about is a tool that shows GNOME about box, and you can use this tool to determine the GNOME version of your desktop.
$ gnome-about --gnome-version
Version: 2.28.2 Distributor: CentOS Project Build Date: 10/10/2012
If gnome-about command is not found in your desktop, it means that you are using GNOME 3.0 and higher. In that case, use the second method.
Method Two
The second way to find GNOME version is as shown below. This is output for Fedora 18.
$ gnome-shell --version
GNOME Shell 3.6.2
Note that Ubuntu Desktop does not come with gnome-shell installed by default. Thus the above command will produce the following error message instead on Ubuntu Desktop.
The program 'gnome-shell' is currently not installed. You can install it by typing: sudo apt-get install gnome-shell
In this case, you can query APT’s package cache to find out the version of GNOME for Ubuntu Desktop. To do so, use the following command. This works whether or not gnome-shell is installed.
$ apt-cache show gnome-shell | grep Version
Version: 3.6.1-0ubuntu1