What is the history of "Modulex" blocks? I have seen a few very small models using something called "Modulex" pieces and have even heard that they are somehow directly related to LEGO? They don't seem to be around anymore so I was wondering what their history was?
Modulex bricks were produced by LEGO mainly for architects as the dimensions were more easy to scale up (they are 5mm in all directions).

You can find a full history (which I confess I didn't read) here

In time, Modulex started to focus more on signage and separated from LEGO, but it still exists nowadays.