Originally Posted by Arevos

Ruby's a general use programming language, but, like Python, Ruby allows a developer to program in a more abstract fashion than in C, Java or even C#. Because of Ruby's dynamic nature, creating classes and methods that are modified and created at runtime is easy enough to be advantageous to use in day-to-day programming. When I'm programming in Java at work, I frequently find myself coming up with a short solution, then having to unravel it until it fits in with the more limited development environment of the JVM.

In short, Ruby's a more agile environment to develop in. In general, an intelligent programmer can create and modify programs faster in Ruby than would be possible in other, less abstracted languages. Unfortunately, Ruby pays for this in speed. Ruby programs are a lot slower than the equivalent Java or C# program. Whether this slowdown is significant depends on what software you're developing. Ruby's had particular success in the web-application market with Ruby on Rails, because serving web pages doesn't often tax CPUs very much.