How do online compilers work?

Question

Web development

There are many online compilers, for example:
ideone.com
compileonline.com
and others.
Approximately the same thing is implemented in automatic systems for sports programming.
Pretty cool thing, I would like to do something like that. But I can't figure out how the server side compilation happens and how the results are pulled.
Are there any detailed articles on this topic or other similar information?

Answer 1

the code is compiled in the background (roughly speaking commandline), executed, the output is written to a file / database, then shown in the browser.
that's the whole article.