Try Ruby is a place to play with Ruby within your browser. You can type commands and get results without having Ruby installed on your local machine. Of course you cannot do all you want with the "Try Ruby". It is just for trying and not for hacking.
If you get stuck, just type "help". or if you find an interesting object, you may be tempted to find out just what it can do,
you can get a list of all the methods to which it will respond with "methods" method call.
Ex: "Must@p".methods
will returns all methods to which the string object will respond.