I would like to install mono-complete so that PlayOnLinux will work properly. http://www.mono-project.com/download/
This post describes how to install MonoDevelop on Ubuntu 17.04: How to install MonoDevelop on Ubuntu 17.04?
In my Ubuntu Software, searching for "mono" does bring up an entry for "MonoDevelop" (Develop .NET applications in an Integrated Development Environment).
Will MonoDevelop work for my needs even though I'm not trying to develop anything?