Zoroastrianism Explained

The so called new religious movements are a guilty pleasure of mine. Some of their followers often claim to be inspired specifically by Zoroastrianism.

But what is zoroastrianism? Apparently, it all started ~3000 years ago in the area currently known as iran, by the guy called Zarathustra. And although the number of active practitioners is rapidly declining, the ideas behind it affect us all to this day, as the christianity and islam seem to be highly inspired by the ideas behind zoroastrianism.