Speaking of Nautilus, Linux Mint isn't the only distribution that wants to use its own custom Nautilus; SolusOS 2, a Debian-based Linux distribution currently in alpha that uses the GNOME fallback session as default, uses a customized Nautilus too.
It's not a fork but it comes with some cool patches that bring an unified, customizable toolbar with the back/forward buttons on the left, as well as some smaller patches like for instance a patch to restore the ability to create a .desktop launcher from the Nautilus context menu.
In SolusOS' Nautilus, the toolbar spreads across the whole window width and is sensitive to the active pane, so only one toolbar is used wen using the extra pane (F3) feature. Also, from the preferences (Edit > Preferences > Toolbar tab), you can select which icons to display/hide: up, refresh, home, computer, search icons and also, the old location bar / path bar toggle button which was removed from Nautilus a while back.
Install SolusOS patched Nautilus in Ubuntu
To make it easy to install for Ubuntu 12.04 users, I've uploaded SolusOS patched Nautilus in a PPA. Add the PPA and install the patched Nautilus (it includes SolusOS patches as well as the patches used by Nautilus in Ubuntu 12.04) using the following commands:
sudo add-apt-repository ppa:webupd8team/experiments sudo apt-get update sudo apt-get dist-upgrade nautilus -q
If you want to revert the changes and go back to Nautilus from the official Ubuntu repositories, use the commands below:
sudo apt-get install ppa-purge sudo ppa-purge ppa:webupd8team/experiments