Introduction
So you're looking for a package containing a file called System.Windows.Forms.dll and Mono. I just checked my installation of 13.10, and Windows Forms 2.0 is not installed.
Using the Code
To install Windows forms 2.0 on Mono, just open a Terminal and type the follow commands:
sudo apt-get install libmono-winforms*
(optional) You might need to install System.Runtime package as well:
sudo apt-get install libmono-system-runtime2.0-cil
