What's so special about Ruby, anyway?

I remember researching Ruby (the programming language) for a class in college, but I remember it being really hard to find documentation for and a little difficult to read. I’d heard how people really love Ruby on Rails, but Ruby itself seemed like an archaic language with no real-world applications. What does Ruby have that other languages (Python, PHP, C++, Java, etc) don’t have? What’s makes it so special?