We regularly look at the state of Jython and, also unfortunately, current qooxdoo (0.8.x) does not work with Jython 2.5.1. The implementation fails at the massive use of regular expressions in our parser. The error reported is a maximum recursion limit exeeded, which seemingly cannot be fixed from within the Python layer (e.g. with sys.setrecursionlimit). So Jython support for qooxdoo is still missing, and qooxdoo users looking at this platform still have to wait.