This is my Parametric, OpenSCAD, Open Source (GPL V3, unless that doesn't work in which case this is CC-BY-SA), bill frame. You could use it to frame other things but I'm using it for a dollar bill.
I recently finished making my first $100 so I decided to make a dollar bill frame to 3D print to hang on my wall.
I decided to come back to this because I remember it was unfinished and it was always something I wanted to do, and glancing at the code I could see that nothing made sense and I remembered that it was not parametric in a couple of places. Now, with 10 modules, about an hour of work, 19 variables, and a total of 184 lines of OpenSCAD code I've commpletely overhauled the code and I'm done. I've completely redone this version. Almost ever line of code has a comment explaining its purpose, for both myself and the user. Everything's parametric including some things that have "modes" depending on how you want to use them. I'm proud of this, and I think I'm finally done.
According to OpenSCAD "Object may not be a valid 2-manifold and may need repair!" so I'm going to always upload a version of the file that I repair with MeshLab. That will be labeled "repaired". A version without comments from OpenSCAD is up also.
Lucas