Many organizations use connectors to interface OpsMgr with third party monitoring solutions.  Recently, Microsoft acquired the Engyro suite of connectors – which are widely used and have historically been third party additions to the MOM/OpsMgr environments.  With the Engyro acquisition customers are able to obtain full support for these connectors directly from Microsoft and, the best part, all Engyro connectors are now available free of charge!  This is a recently announced change but you should see availability soon.  The details of how these connectors will be obtained are still being worked out.