Many have yet to learn the history of alternative implementations like egcs, IronPython and IronRuby, jpython and jtcl, PyPy, Rubinius,...
Most of the time switching is not worth the effort for the few things they do better than the original implementation, and eventually if the features are really relevant enough, the main implementation will end up having them as well.
Most of the time switching is not worth the effort for the few things they do better than the original implementation, and eventually if the features are really relevant enough, the main implementation will end up having them as well.