RabbitVCS is a set of graphical tools for accessing the version control software that you use. It supports Subversion and git and is similar to TortoiseVCS found on Windows.
Ubuntu 12.04 provides RabbitVCS in the standard repositories but this is version 0.13 which does not have support for GNOME 3 and so does not provide nautilus integration or gEdit integration.
In order to install the later 0.15 version of RabbitVCS you will need to add the RabbitVCS ppa. To do this add the following repositories
deb http://ppa.launchpad.net/rabbitvcs/ppaubuntu precise main deb-src http://ppa.launchpad.net/rabbitvcs/ppaubuntu precise main
Reload the changes and install packages rabbitvcs-core, rabbitvcs-cli, rabbitvcs-nautilus3 and rabbitvcs-gedit. You will need to log out and in again for the changes to take effect.