(From Wikipedia) "Costa Botes assembled documentaries about the making of the Lord of the Rings films, as a result of reputedly being a close friend of Jackson. Botes' films, with no narration, no interviews, and no commentary, include behind-the-scenes footage collected over a five year span."
What's interesting is that because New Line Cinema did not authorize his project, Botes could not release the documentaries to the public. So I guess New Line must have authorized it for this release.