Code Playground platform

Question

I wonder on which platform runs every Code Playground language... (OS, compiler version) 
Specially in C. I got different outputs in CP and in command line (GCC 5.4)
As an example, see attached C program...
Thanks!!!
https://code.sololearn.com/c64wiXlKCM99/?ref=app

Answer 1

Thanks!

Answer 2

Shows os &compiler version when coding in C
https://code.sololearn.com/c14uRJJoXcX6/?ref=app
Edit: added python, php, jsva code snippets that shows system info: https://code.sololearn.com/c1ap23iOjUx8/?ref=app
https://code.sololearn.com/weC1fAD70ERe/?ref=app
https://code.sololearn.com/c2bRnBov0mN2/?ref=app