Arrives with v1.
The same controls, arranged two ways. V switches between them.
Perform
The picture gets most of the window, with the layers and parameters in a rail beside it. This is the view a show runs in, and it is the default.
Build
The columns, with the parameters widest. This is the view a show is prepared in, where you are reading names and ranges rather than watching the output.
What does not change
Nothing exists in one view that is not in the other. There is no control hidden in Build that you will go looking for mid-set, and no shortcut that only works in one. The keys are identical.
The choice is remembered on this machine and never travels in a show file. Open somebody else's show and you get your own arrangement, not theirs, the show is the work, the view is the desk you sit at.