gdm3 software package provides Next generation GNOME Display Manager, you can install in your Debian 7 (Wheezy) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install gdm3
gdm3 is installed in your system.
Make ensure the gdm3 package were installed using the commands given below,
$ sudo dpkg-query -l | grep gdm3 *
You will get with gdm3 package name, version, architecture and description in a table
| Distro | Debian 7 wheezy |
| Section | GNOME |
| Package | gdm3 |
| Version | 3.4.1-8 |
| Description | Next generation GNOME Display Manager |
| Sub Section | GNOME |