Hi Colin,

> Running the latest v4 Beta Mac Version (on El Capitan, 10.11.6) when I create second window a new
> moi3d app is launched, Just checking this is not the expected behaviour ?

Yeah unfortunately this is going to be the way that I have to make it work. MoI expects that each main program window has its own thread and process but there isn't any way on Mac for multiple processes to share a single dock icon.

The way that Apple has implemented multiple windows in its standard application infrastructure is problematic because they have them all inside the same process and sharing a single UI thread which means they can interfere with each other in various ways. If one crashes for example they all crash because they aren't running in separate processes.

So this (multiple app windows) is an area where the standard Apple way is just not good and I don't expect to have MoI follow the standard behavior for this particular thing.

- Michael