Timeline of Java Platform Releases
- 1996- JDK 1.0
- 1997- JDK 1.1
- 1999- JDK 2
- 2004- J2SE(TM) 5.0
- 2006- Java SE 6
The numbers and letters that indicate a new software release are not always obvious. As a general rule, though, new versions of software have a higher number than the last version. The version numbers for Java follow this rule, but with a few caveats.
With time the Java technology has evolved and changed. Minor upgrades, bug fixes, and new functionality are part of the typical release process, and you will see new numbers attached to the end of any software program when an update is released into production. Think of Windows 3.1 which eventually became Windows 95, then Windows 98, Windows 2000, and now Windows XP.
When Java was first released, it was duly dubbed Java 1.0, or JDK 1.0, in 1996. The first version of any software, whether it’s a game or a how-to-type application, will typically be version 1.0. This is not absolute law, but most companies developing software today follow this guideline.
As bugs are discovered and fixed (there is no such thing as bug-free software), minor upgrades to the software are released to the general public. These minor release numbers are incremented at the decimal level, but Java versioning is a little different. For example, the Java platform upgrade from 1.0 to 1.0.1 was not a major upgrade. The last decimal, .1, indicates that this was a minor upgrade from the 1.0 version.
You would think that the natural progression would have been for Java’s next major upgrade to be called Java 2.0, and it was. Sort of. The 2.0 in Java actually represented version 1.2.0. This was getting a little weird, but just as I was starting to see the pattern, Sun Microsystems changed the official naming convention.
Lately, you may have seen books or web pages referencing Java 5 and Java 6. I was starting to get a little worried, thinking that maybe I missed Java 3 and 4. I didn’t miss much, other than Sun’s change in naming conventions. Here’s what Sun has to say about the recent name changes:
The current release is Java Platform, Standard Edition 6 (Java SE 6). The previous release was Java 2 Platform, Standard Edition 5.0 (J2SE 5.0). Sun Microsystems simplified the platform name in 2006 to better reflect the level of maturity, stability, scalability, and security built into the Java platform. Sun dropped the "2" from the name and deleted the "dot number" (the number following the period). Any updates to Java platforms will simply be noted as updates rather than adding a "dot number" at the end of the platform name.Well, let’s hope that the folks at Sun stick with this latest naming convention. It’s an exercise just trying to keep up with versions!
Source: Sun Microsystems