A dynamic, open source programming language with a focus on simplicity and productivity. It has an elegant syntax that is natural to read and easy to write.
It has more qualities:
Terse. Short, but still easy to understand.
Dynamic. Easy to change, any time and any where.
Duck typing. If you think you understand it, you probably understand it.
Many programmers like it because the creator tried to make it easy and excellent to use.
Introduction to RUBY