I set out to make a reliable film camera anyone can make out of common materials. There are versions for 35mm and 120 in both 6x6cm and 6x9 sizes. Templates for several distances to the pinhole are available.
The main instructions for building them are at: 10th Anniversary Populist Plans.
The Compact Series.
The distinguishing feature of the Compact series is that they are about the smallest 6x6cm medium format cameras possible. Just barely taller than the 60mm width of 120 film and only 95mm wide. A Populist of similar format is 130mm wide. They also have a feature to keep the winders in place without a separate WinderMinder. I think, if put together correctly, they are about the most reliable and light tight cameras I've ever made.
Some key posts in the development.
The Variable Cuboid Pinhole Camera System.
The Variable Cuboid system consists of a film back and fronts with different angles of view. It requires a darkroom or changing bag to change the front while the back is loaded with film.
This original description of the camera is at: The Variable Cuboid Pinhole Camera System
Detailed directions to make it are at: Building the Variable Cuboid System
The Pinhole Lab Camera.
A camera design for using photo paper negatives with the objective to allow students to experiment with multiple aspects of pinhole photography such as distance to the pinhole (what would be focal length on a lens), pinhole size, rising and falling fronts and flat and curved film planes. Available for negatives 2.5 x 4 inches and 4x5 inches.
The original description is in the post The Evolution of the Pinhole Lab Camera
Detailed instructions on making it are at: Building the Pinhole Lab Camera.