I upgrade ubuntu 13.10 from the development branch (alpha version or beta version) and after that at login user only two options are available. here I am attaching an image of gnome metacity
What are these versions of Gnome and I would like to know what is the difference?
for how to get back ubuntu default I asked here another question and here is a link for that same question
The backend is different: Compiz uses a 3D compositor to display the windows. Whereas Metacity displays the windows in 2D. So if you have a low end graphics card and/or want to save energy on a mobile device I would suggest that you use metacity.
There also used to be problems with 3D applications in combination with compiz.
In my experience falling back to gnome after installing Trusty, these answers are not fully adequate. I found the Metacity option preferable to the compiz for two reasons right out of the box. Metacity comes set up with four workspaces, while this has to be configured in compiz and I found the configuration not straightforward as apparently there are two competing window managers. Further Metacity will consistently put the menus on the panel where I expect them whereas the compiz version did not always do this.
