Random class that supports various random number generators
Time is reimplemented. There is no longer the year 2038 problem.
some regexp enhancements
$: no longer includes the current directory.
dl is reimplemented on top of libffi.
new psych library that wraps libyaml. You can use the library instead of syck.
Ruby is a reflective, dynamic, object-oriented programming language. It combines syntax inspired by Perl with Smalltalk-like object-oriented features, and also shares some features with Python, Lisp, Dylan and CLU. Ruby is a single-pass interpreted language. Its main implementation is free software.
Ruby Programming Language Features
Ruby has simple syntax, partially inspired by Eiffel and Ada.
Ruby has exception handling features, like Java or Python, to make it easy to handle errors.
Ruby's operators are syntax sugar for the methods. You can redefine them easily.
Ruby is a complete, full, pure object oriented language: OOL. This means all data in Ruby is an object, in the sense of Smalltalk: no exceptions. Example: In Ruby, the number 1 is an instance of class Fixnum.