> We want a Swing 1.1, then a 1.2, then a 1.3....without backward compatibility. Are you kidding? Remember on the version hell of Java 1.2.x.. The backward compatiblity is one of the best features of Java and Swing. How many Java-Versions do you want to install to run all still existing Java-programs? And with how many Java-Versions do you want to try any Java-program until you have find the right Java for your program?

modularisation won't do what you want. Permgen leaks are almost universally called by calling String.intern() excessively, the use of which is almost always a design or implementation flaw in copying or cloning operations.

quite apart from that (which I don't mind all that much as the Sun JVM is thee de facto standard all others (should) comply with), it will introduce a whole new level of DLL hell. Imagine a dozen applications on your machine, all using the same JVM, but each requiring a different subset of different versions of the modularised core libraries. You'll no longer be able to rely on anything being available on a user's system, which is especially worrying when that machine is situated byhind a strict firewall that doesn't allow for downloading of components you need (which is the reality for a large portion of the professional developers creating Java software for use in companies and government departments). Instead of just telling the sysadmins that JVM version X or better is required (which they can easily provide for, after several months of testing to ensure it is "safe" for use on the network), you'll have to provide a comprehensive list of which subversions of which jars of the modular system are required, each requiring that testing cycle. Before you know it those sysadmins will decry they'll no longer approve any Java software for deployment because the process is impossible. It's happened in the past when even the need to have a JVM at all was seen as an insurmountable obstacle by sysadmins. They've gotten over that, don't bring it back now. And then there are the people who don't have uninterrupted internet connections at all, relying on slow modem connections. A modular JVM that downloads (or tries to) libraries on the fly as needed will cause those people lots of headaches, and may not work at all if they have to rely on physical media for software distribution.