Basically Ruby is a scripting language for easy object programming. It process text files and to system management tasks (as in Perl). It is simple, extensible, and portable.
You can write small and large scale web applications from scratch or based on the popular Ruby web framework

The important feature that it is totally free, not only free of charge, but also user friendly to use, easy to copy, modify, and distribute it.
Main Features are:

* multiple precision integers
* convenient exception processing
* dynamic loading
* threading support
* Ruby comes with simple syntax,
* Ruby has extraordinary features, like Java or Python,which make it easy to deal with errors.
* Ruby’s operators are syntax sugar for the methods. You can redefine them easily.
* Ruby’s designed to be both complete and open for improvements Ruby has the ability to add methods to a class

What makes Ruby so popular? Ruby weaves the best features of the best programming languages into a seamless, concise whole.