On behalf of the Jython development team, I'm pleased to announce that Jython 2.5a0+ is available here http://downloads.sourceforge.net/jython/jython_installer-2.5a0.jar for download. See http://jython.org/Project/installation.html for installation instructions. This is the first alpha release of Jython 2.5 and contains many new features. In fact, because we have skipped 2.3 and 2.4, there are too many to even summarize. A few of the features are: * generator expressions * with statement * exceptions as new-style classes * unicode support more in line with CPython * decorators Under the hood Jython 2.5 has a new parser based on ANTLR 3.1 and the compiler has been refactored to use ASM. There are so many more changes that I have missed more than I have listed. This is an alpha release, so there are known and unknown bugs, so be careful.