There is very little public information about the filmmaker now, and even less when the movie came out. As a result there was considerable speculation as to who this person is and what are his motives. Clearly the Zeitgeist movie is intended to persuade toward a point of view to the point of ignoring and manipulating the facts in pursuit of an agenda. So knowing more about the filmmaker can be tremendously insightful.
So who is "Peter Joseph"
Frankly we do not know very much. The filmmaker has been very secretive until recently when he did an interview with Alex Jones.. We invite the reader to watch it if they are interested. And if they wish to send us a critique, that would be useful
"James Coyman" a pseudonym?
It was wildly reported/speculated that "Peter Joseph" was a pseudonym for James Coyman.
Since then "Peter Joseph" has provided a occasional public glimpse. In addition, the Zeitgeist web site added a Q&A that flatly denies the "Peter Joseph" is a pseudonym for anybody. 
While not 100% conclusive, it is our judgment, based on the current 'best available evidence', is that "Peter Joseph" is indeed a really name.
This also raises some skepticism about one site www.zeitgeistmoveisfake.com web which seems convinced of the pseudonym allegation, and also claims to have other inside knowledge about the film. Webskeptic had considered "zeitgeistmovieisfake.com" as 'speculative' but now judges it to be 'unreliable'. This does not mean we think it is mostly true or mostly false; just there is insufficient evidence to declare it either way.