These documents under the "Private" heading can be used to run MMDTs yourself. They include character sheets, impressions sheets, clues, and a basic plot overview for the MD.
Blank templates are designed for people who want to write their own MMDT. They serve as a fill-in-the-blank style framework to get you started thinking about characters and plot.
"Private" templates are designed for groups in which everyone participating will be a character. (i.e. There is no audience)
"Public" templates are more like loosely-scripted plays in which a set number of people perform a mystery for an audience. It's the audience's job to figure out who the murderer is.