After having followed twisti’s build instructions on how to build cacao with OpenJDK as runtime, I’ve got an OpenJDK based JRE with Cacao as VM in JIT mode on s390. Here’s the usual first real life app run:

$ ~/j2re-image/bin$ ./java -cp /usr/share/java/jython-2.1.jar org.python.util.jython
LOG: [0x77e626b0] JVM_GetStackAccessControlContext: IMPLEMENT ME!
LOG: [0x77e626b0] JVM_DesiredAssertionStatus: cls=0x475d20, IMPLEMENT ME!
LOG: [0x77e626b0] JVM_DesiredAssertionStatus: cls=0x474d20, IMPLEMENT ME!
LOG: [0x77e626b0] JVM_DesiredAssertionStatus: cls=0x475a80, IMPLEMENT ME!
...
LOG: [0x77e626b0] JVM_GetSystemPackage: IMPLEMENT ME!
Jython 2.1 on java1.7.0-fastdebug (JIT: null)
...
>>> import java.lang.System as s
LOG: [0x77e626b0] JVM_GetProtectionDomain: cls=0x5fed20
LOG: [0x77e626b0] JVM_ResolveClass: IMPLEMENT ME!
>>> [s.getProperty(p) for p in
    ['java.vm.name', 'java.runtime.name', 'os.arch', 'java.vm.info', 'java.version']]
LOG: [0x77e626b0] JVM_GetProtectionDomain: cls=0x5fed20
LOG: [0x77e626b0] JVM_ResolveClass: IMPLEMENT ME!
['CACAO', 'OpenJDK Runtime Environment', 's390', 'JIT mode', '1.7.0-fastdebug']