Java Version History article describes about the history of the different java versions released.
From it's inception, java language is undergone several changes.
Java's first version (JDK 1.0) was released on the year 1996, January 23 and first version's codename was oak. This release consists with 8 packages and 212 classes
From version 1.4, Java language development is undergone according to the rules of Java Community Process (JCP), and they uses Java Specification Requests (JSR) to propose and specify improvements and changes to the Java Language.
JCP helped the development process of java language to become a community driven to a greater extend