I need to run two different versions of mono at the same time for two separate applications on ubuntu 16.04. is this possible? How can I go about doing this?
So expand my comment above as it turns out to be useful.
Virtualization You really should use a virtualization technologies to build Mono environments, so
Parallel Mono This is a very special setup Mono team used to document when developers have a default Mono installation from the Linux official repo, while would like to also build Mono from source code for experiments.
The steps were documented in an article.
My personal suggestion is that you go the virtualized ways, and most should use Docker today.