Early release of IBM's Java 6

The Early Release Programme for IBM's Java SE 6 on a number of Linux platforms just began.

Apart from the functional enhancements inherent in Java 6 and the additional performance and RAS features we put into this release, there were significant changes in the development process.

Of particular note is the way we handled the class library code licensed from Sun. In Java 5 and other recent releases, we carried forward a base from release to release and merged in Sun's changes -- fairly labour intensive. This time we introduced a much more efficient process.

We developed a system to capture the IBM changes to Sun code such as bug fixes, performance improvements, and support for IBM platforms. Each logical group of changes is captured as a "smart patch" based on a UNIX patch file. The system automatically applies all the smart patches to each new drop of Sun code. Manual intervention is only required where the Sun code has changed significantly in an area covered by a smart patch.

The net effect is that we have been able to track the development of Sun's Java 6 much more closely than in the past. Also, the changes we make have been separated out in to logical, manageable units.

I'm hoping to contribute the smart patch system into open source as it would be useful to any project that needs to apply its own changes to a moving base.