How to compile .cs (c#) file on server?

Question

Programming

Task: on a website hosted on azure, compile downloadable c# .cs files into .exe, then run them through tests like the site acm.timus.ru
Are there portable versions of the compiler for this and how legal can they be used?

Answer 1

https://msdn.microsoft.com/en-us/library/78f4aasd.aspx