I've installed mono and MonoDevelop on a Fedora 20 x86_64 KDE and it's working. I've been using this for many months now, and never had one problem.
There is some problem with Monodevelop on Gnome.
I got the latest versions from this repo, the guy who built it said that you could try to use the Centos repo/packages for rhel 6.5 Workstaion.
Excerpt:
For CentOS CentOS-7 run the following as root:
cd /etc/yum.repos.d/ wget http://download.opensuse.org/repositories/home:tpokorra:mono/CentOS_CentOS-7/home:tpokorra:mono.repo yum install monodevelop-opt
For CentOS CentOS-6 run the following as root:
cd /etc/yum.repos.d/ wget http://download.opensuse.org/repositories/home:tpokorra:mono/CentOS_CentOS-6/home:tpokorra:mono.repo yum install monodevelop-opt
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4.sept 2018:
He is still maintaining monodevelop-opt for debian and ubuntu