Update: As of September 27, 2018, ISAAC is no longer available on this domain. The links to to it have been removed from the post below, though the remainder of the content has been left unchanged.
ISAAC’s code is still available on GitHub.
A quick video showing some of the things coming out in ISAAC Release 2: camera transitions, object labels, and Velocity/Acceleration lines.
(And a way to reset the simulation without refreshing. F5 be gone!)