The naming and versioning of
Java versions has been a bit irrational in the past.
First, there was Java 1.0 and 1.1.
Then there was Java 1.2 and Sun decided to call this "Java 2" for some reason.
For version 1.3, 1.4 and 1.5, it was still called "Java 2" - "J2SE" (Java 2 Standard Edition) version 1.3, 1.4, 1.5. For version 1.5 the situation became even worse, because it got the version number 1.5 as well as 5.0. Sun has some strange reasons why they think this was a good idea, you can read about it here:
Version 1.5.0 or 5.0?.
Now, Sun has discovered that the "2" actually doesn't mean anything, so the next version of Java is going to be called "Java SE 6" (Java Standard Edition version 6, or 1.6).
Likewise with
J2EE, which is now going to be called Java EE 5 (Java Enterprise Edition 5).
[ July 24, 2006: Message edited by: Jesper Young ]