The problem with most great projects written by small group of brilliant people in any language:

- it introduces its own vocabulary, it looks like gibberish until you build up the context

- since the group is small and gifted they have no problem creating and using the power tools of their own

- there is no documentation so your only way is through experimentation and direct communication

- the folks who have built it had to move on to solve another (bigger) problem, leaving no traces of what the vocabulary is, where the design was headed, what should be changed with the new requirements and again next to zero documentation