I am kinda of a new user here and don't have enough reputation points to comment/ask on this question: IDE support for Hack Lang.
So, I am hoping that since the last entry provided by Themis Beris someone has been able to get PHPStorm working properly with Hack. I followed the 3 steps described in the post I mentioned, but still get compile-time errors on the classes I've written using Hack. <?hh is not recognized, for instance.
Any suggestions as to how to get PHPStorm playing nice with Hack?
I have no idea what Themis Beris is talking about on the linked question. (He seems to be saying something about PHPUnit, which is a completely separate issue.)
JetBrains has a feature request open for Hack support and last I heard was very actively working on it. But as of this writing (Feb 2015) it's not released yet.