This is a step towards Ticket #40360 without going all the way. You can
open additional viewer windows. They are not connected by an
Oberon-style messaging system (yet. It would be nice to use the Tk event
system for that.)
This way the log and the main/scratch/system-menu text are conceptually
unified in the (equivelent of "desktop") base metaphor of the system.
Now the UI highlights commands and numbers as you move the mouse, numbers
are blue, commands that type-check are green, commands that fail to
type-check are orange and will not be interpreted, and if there is no
stack effect information available for a command it is grey but you can
still attempt to execute it.
You can still evaluate whole expressions by selceting them and
right-inter-clicking before you release the left button, or by putting
the cursor on a line and typing ctrl-enter, which will run the whole
line. These expressions are NOT (yet) type-checked.
Simon Forman