Note that I mentioned JVM 5, not Java 5.

Since Chronon requires running on JVM 6, we do get people time to time asking "Does that mean Java 5 is not supported?".

Backward Compatibility

It seems some people still don't understand that you can run Java 5 code on JVM 6. The JVMs are, and have always been, fully backward compatible.

This also means, that you can still write your code as Java 5 and even use JVM 5 to compile and build your  application, but during deployment you can choose JVM 6 instead of JVM 5 and gain all the advantages of using a more recent JVM while making sure your code still can, if really needed, run on JVM 5.

Disadvantages of JVM 5

The JVM 5 is over 7 years old. It was even End Of Life'd over 2 years ago.  That means it won't be receiving any more updates, so if you run into a jvm bug, tough luck... On Macs, its not even possible to install JVM 5 unless you use some hacks.

Frankly, why anyone would use a a 7 year old technology which won't receive any new updates, when a perfectly good alternative is available, is beyond me!

Advantages of JVM 6

The JVM 6 has been with us for > 5 years now and is still very much under active development. It has had 29 updates so far and is used by millions. It has much better performance than JVM 5 and the vast number of updates have ensured it is pretty damn stable.

Conclusion

At this point it baffles me that enterprises are sticking with a 7 year old, discontinued technology which has a perfectly good replacement which performs better and gets active updates. JVM 5 is the new IE 6 and like IE 6, it would be good for everyone if it was completely eradicated from this world.

Source: http://eblog.chrononsystems.com/jvm-5-is-the-new-ie-6