Yesterday morning, I gave a presentation at the 2015 OpenFabrics Software Developers' Workshop.  I discussed the status of libfabric support in Open MPI.

Here's a copy of my slides:

In short, the Open MPI development master (what will eventually become v1.9) contains two different plugins that use libfabric:

1. The usnic BTL (which I've mentioned on this blog before)
2. The ofi MTL

The two plugins (currently) target different networking hardware, and use different portions of the libfabric API. As such, these two plugins provided excellent feedback to libfabric, in an MPI-libfabric co-design sense.

There's still much work to be done in libfabric, but having a real, production MPI implementation using libfabric in multiple different ways has been extraordinarily useful.