All OpenIndiana system software was rewritten in Python 3. Installation images now don’t deliver Python 2.7 interpreters or libraries, however some software still requires Python 2.7. We’ve moved to GCC 7 as the default compiler.
OpenIndiana Hipster is a rolling release distribution of illumos, which in turn traces its roots back to OpenSolaris. The original intent of illumos was to replace the closed source parts of OpenSolaris with open source ones, but after Oracle discontinued OpenSolaris, illumos grew into a full-blown fork of OpenSolaris.