How does Ctrl + K work in Stack Overflow? [duplicate]

Question

I am very curious to know how to implement the Ctrl-K (code sample) feature against code.

For example:

public static void main(String args[]){        
    System.out.println.out("welcome");
}

Will that be nicely formatted?

1. Do we require any package to implement this?
2. Any ready made code available to do this?

I am planning to develop a site where this feature would be really helpful.

Answer 1

I guest you are looking for Google Javascript code prettifier.

As rsp mentioned in comments it works for the following list of languages.