Xamarin should be doing a better job at publishing the linux packages in a one-click manner. I don't care what linux distro (SuSE, RHEL, CentOS, Ubuntu etc) - just pick any one as the supported one and publish for it. It seemed that it used to be SuSE but even that has old packages as seen within Zypper/YaST.
Update Mono framework
Having said that, to update the Mono framework itself, without letting go of the package managers try this. This will work as long as the project dutifully publishes the RPMs. You don't want to build from source since it's a more fickle process and the setup distracts from your real objective (i.e. develop).
Obviously, please replace the URL below to what will be latest by the time you're reading this.
mkdir mono-rpms
cd mono-rpms
wget --reject "index.html*" -nd -r -e robots=off --no-parent http://download.mono-project.com/archive/3.2.3/linux/x64/
sudo zypper install *rpm
Update MonoDevelop (the IDE)
Timotheus Pokorra's answer indicates he's filling in some of the usability void left by Xamarin (Thanks Timotheus!!). You can install MonoDevelop via
http://software.opensuse.org/download/package?project=home:tpokorra:mono&package=monodevelop-opt
Note that on SuSE I get the error
Problem: nothing provides liberation-mono-fonts needed by mono-libgdiplus-opt-3.0.12-7.1.x86_64
Solution 1: do not install monodevelop-opt-4.0.12-5.2.x86_64
Solution 2: break mono-libgdiplus-opt-3.0.12-7.1.x86_64 by ignoring some of its dependencies
I (very reluctantly) selected to break the dependency. Note that I already had liberation-fonts
(via sudo zypper install liberation-fonts
). I don't know if its the same/different as liberation-mono-fonts
. Anyway, hope Timotheus fixes it when he has a moment.