It has been around in one form or another for many, many years. Back 10 years or so ago there used to be a regular Tuesday night chat session, if memory serves me. It was always lots of fun.
Back when I could spend more time on the board I would always log into chat just in case. Had some great one on one conversations with various members that did the same thing.
It is Java driven which may be why it doesn't work on your Mac. OS X automatically disabled the earlier versions of Java, if you want it to work, download the latest Java 8u25.