Lambda the Ultimate

The article highlights several interesting features of Ruby,

Yukihiro Matsumoto, aka Matz, has said that "The purpose of Ruby is to maximize programming pleasure", and experience has taught me that enjoying the creative process leads to faster development and higher quality code. Ruby features powerful object-oriented abstraction techniques, extreme dynamism, ease of extensibility and an armada of useful libraries. It is a veritable Swiss Army machete, precisely the sort of tool one should bring into uncharted territory such as the NFS-mounted priority queue I was seeking to build...

One of the things to note about this extension is I actually was able to add a method to Ruby's built-in File class. Ruby's classes are open--you can extend any class at any time, even the built-in ones. Obviously, extending the built-in classes should be done with great care, but there is a time and a place for it, and Ruby does not prevent you from doing so where it makes sense. The point here is not that you have to extend Ruby but that you can. And it is not difficult to do...

In Ruby a module not only is a namespace, but it can be mixed in to other classes to impart functionality. The effect is similar but less confusing than multiple inheritance. In fact, Ruby classes not only can be extended in this way, but instances of Ruby objects themselves can be extended dynamically with the functionality of a module--leaving other instances of that same class untouched.