After noticing that all reference to the focusing viewer had been
removed from the 3D World website, I contacted them to find out its
status. This is the reply I received:

"Unfortunately, the designer had an accident and we have to put it off
and the information about it on the website was removed. But we didn't
abandon this viewer. We are still working on it."

I don't know how serious was the accident but from the tone of the
message, it appears to have paralysed progress on the new viewer.
Let's wish the designer prompt recovery.

Francois