Good news. Brian Zimmer has announced on jython-dev that he and Samuele are merging the new style classes branch into the trunk: Samuele and I collaborated today on getting his changes for new-style classes checked into the tip and I just finished committing everything. The changes are extensive and quite exciting. While not all core types are converted a number have been and over the next couple of days I"ll work on migrating the rest. It"s likely this code will change a bit, especially where the generated code will eventually live, but please give it a try and let us know how you fare....