On WebUpd8 I found this article about installing MDM (Mint Display Manager). I thought it was an interesting article and i wanted to mention MDM on n00bs on Ubuntu and with Andrew’s permission… here is a guide to install MDM on Ubuntu 13.04. All credits go to Andrei for the article and images, I only recorded and added the video. You can install MDM by adding the WebUpd8 PPA.
Important: installing MDM will remove GDM (and GNOME Shell, since it depends on GDM – but this is only for Ubuntu 12.10 and 13.04). That’s because there are some conflicts between MDM and GDM. So if you’re using GNOME Shell in Ubuntu 12.10 or 13.04, do not install MDM.
To add the PPA and install MDM open a terminal window (press Ctrl+Alt+T) and copy+paste the following lines:
sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install mdm ubuntu-mdm-themes

During the installation you will be asked which display manager you want to use as default display manager (select MDM). LightDM is the default display manager for Ubuntu and MDM is the default display manager for Mint.
Once MDM has been installed, restart you computer. Until you restart the computer, MDM Setup (shows up as “Login Window” in Dash / the menu) won’t show up. After restarting the computer, the default (kind of ugly, I know) MDM theme will be loaded – very important: the first time MDM starts, no session is selected so make sure you select one from the drop-down indicated in the screenshot below:

Then you can log in, launch MDM Setup (look for “Login Window” in Dash / the menu) and select the theme you want. From the “Style” drop-down you can select what kind of themes you want to use: GDM themes, HTML themes or GTK (there is only one GTK greeter available by default):

Because the default MDM themes are Linux Mint branded, Andrei tweaked some of them to integrate better with Ubuntu, and renamed the package to “ubuntu-mdm-themes”. But he’s no graphics designer so you may want to tweak them further – this can easily be done since the themes are mostly HTML / CSS, so look under /usr/share/mdm/themes/ for GDM themes and in /usr/share/mdm/html-themes/ for the new HTML themes and change them to suit your needs or create your own theme.
Here are some screenshots of MDM themes:




