As an exercise, construction of the Reuleaux tetrahedron, and the two Meissner bodies can be easily done with Moi commands.
Simple Moi construction of the tetrahedron has been done before.

http://www.swisseduc.ch/mathematik/geometrie/gleichdick/index-en.html

- Brian

Interesting link.
M.

I made some Reuleaux tetrahedra some months back.
Prior to that I made some Reuleaux rollers yoked together. Amazingly they work like cylindrical rollers when used to transport something put on top of them.
Here's a link to a short video I made: http://youtu.be/2CSpXSGFaes
And a link to the 'thing': http://www.thingiverse.com/thing:312621

All, of course, designed in MOI.

Mike.