Question : installing an extrenal script into mikrotik

Hello.
Is it possible to install an external (non-mikrotik related) script into mikrotik routeros?
an script like a radius server manager called Ibsng (a linux based tool )…
if no, is it possible to install linux and mikrotik side by side on a server and use both of them at the same time? (booting both at same time)
Thanks.

No it is not possible to run external scripts on RouterOS

Yes, you can boot more than one OS at the time if one is running as virtual machine. (check KVM on x86 or MetaROUTER on RB).