The latest Synaptic Package Manager from BZR has been ported to GTK3 and the new version will probably be available in the Ubuntu 13.04 repositories. Since many of us are still using Ubuntu 12.10 or 12.04, I've uploaded the latest Synaptic with GTK3 support to a PPA so you can easily install it.
|Synaptic built with GTK3|
On a first look, it seems like nothing has changed - that's because the toolbar was supposed to be dark for GTK3 applications using Ambiance, but it looks like Synaptic is using a custom toolbar, at least for now. But you should notice the difference (e.g. buttons, checkboxes, etc.) once you start using it.
Furthermore, besides the GTK3 port, the latest Synaptic from BZR has got a lot of bug fixes - a complete list can be found here.
Install Synaptic Package Manager with GTK3 support in Ubuntu
Synaptic Package Manager built with GTK3 is available in the WebUpd8 Unstable PPA, for Ubuntu 12.04, 12.10 and 13.04. Currently, there are no other packages for these Ubuntu versions, so the PPA is safe, but at some point I might add some other unstable packages.
Also, this version of Synaptic is currently considered experimental. So use it at your own risk! I can't guarantee everything will work for you, but I can tell you that I'm using it right now in Ubuntu 12.10 and everything works fine.
To add the PPA and install Synaptic with GTK3 support in Ubuntu 12.04, 12.10 or 13.04, use the following commands:
sudo add-apt-repository ppa:webupd8team/unstable sudo apt-get update sudo apt-get install synaptic
Alternatively, you can download the Synaptic deb from our PPA.
If you want to built it from source, you can grab it via Launchpad.