FYI, we just finished the implementation of a ORCA module for the support of a runtime infrastructure developed at Oak Ridge National Laboratory.
For this, we are currently using the version of ORCA available on the bitbucket branch: https://bitbucket.org/jjhursey/ompi-orca
ORCA clearly makes the integration easier and more maintainable; we hope it will make its way back into trunk very soon.
Geoffroy Vallee, PhD
Oak Ridge National Laboratory