To start playing with Ruby, this is a good start: http://netbeans.org/kb/docs/ruby/setting-up.html
Update: Mmm.. http://forums.netbeans.org/topic20818.html
ObjectsAlmost fourty years... that's a lot of time.. Here is the link:
Every entity in Smalltalk's world is called an object. Objects can remember things and communicate with each other by sending and receiving messages. Every object belongs to a class (which is also an object). The class handles all communication (receiving a message and possibly producing a reply) for every object which belongs to it.
Message Sending and Receiving
A message is sent to an object by first mentioning the object and then mentioning the message.
The Notion of Class
The basic class definition deals with just two ideas:
1. The notion of creating objects which have independent existence and memory.
2. The control of the flow of evaluation by sending and receiving messages in various ways.