It is not. No version of Avid MC is at this time. MC 8.4 is compatible with 10.10.3. But 10.10.4 JUST came out, and compatibility isn't there at this time. I don't think they'll make a version of MC 7 that will be compatible...if they (Avid) spend resources and time making versions compatible, it'll be the more recent ones, the ones they can make money on.