I met this problem at the beginning of my work. I am using Mono 2.10 with MonoDevelop 2.8. When I create a new C# project, I can not use:
using System.Windows.Forms
because there is no such namespace here.
I searched for some answer and tried:
apt-get install libmono-system-windows-forms4.0-cil
and
apt-get install libmono-winforms2.0-cil
but they all tell me I have installed them. So now I'm wondering if I can not write windows forms application with Mono but I can only run such application with it?