Right now both api and impl modules claim to export javax.faces package. That's a problem in OSGi environment and actually causes classloading problems. The impl module exports javax.faces package since it contains resource bundles for javax.faces package. Moving the resource bundles to the api module does resolve the OSGi problem and I saw no failures when building the code. I'm building https://svn.apache.org/repos/asf/myfaces/core/trunk.