Gimpel3D
Gimpel3D - 2D/3D Stereo Conversion Editor
...The user works in true proportional space where the scene can be viewed from any location. The scene is edited geometrically in space using tools specifically designed to work with the perspective projection of the image.
This creates a virtual workspace that is intuitive for the user and proportionally accurate.
NOTE: The entire codebase is currently in a single zip file (look under "Files"), and NOT in the sourceforge project repository..