Panels

The dockable panels around the canvas, and how their layout is remembered.

Everything beside the canvas is a panel, and every panel behaves the same way: docked to an edge, floated into a window of its own, or collapsed to a labelled tab on the dock strip. All of them are listed under View > Panels, which is where to go when one has gone missing.

The three states

Docked: takes a strip of the window edge; the canvas gives up the room.
Floating: a window of its own, which can go on a second monitor.
Collapsed: a labelled tab on the dock strip, still there, taking no space until you click it.

The panel's content is the same object in all three states, not three copies of it, so nothing is lost or reset by moving a panel around mid-task.

The panels

Panel	What it is for
Properties	Everything about whatever is currently selected.
Markup	The review list: every markup in the project, one row each.
Tool Chest	The standard tool groups and your saved sets, as a panel rather than a toolbar.
Materials	The materials takeoff module. Documented with Materials Takeoff.
Utilities	The utilities takeoff module. Documented with Utilities Takeoff.

Materials and Utilities are part of the paid feature set, so they appear only where your subscription includes them. If one is missing from View > Panels, that is why. Both are available throughout the trial, which hands out the full product for its whole length.

How the layout is remembered

The layout is saved with the project, so the arrangement you leave a job in is the one you come back to.

Most panels always come back as at least a collapsed tab, even if you closed them, so the dock strip never goes empty and you can always see which panels exist.
The exception is a panel that only opens on request, such as the Tool Chest: close one of those and it stays gone until you ask for it again.

Opening a PDF directly rather than opening a project starts in a clean canvas with every panel collapsed to its tab. Changes made in that mode are deliberately not saved, so a quick look at a drawing cannot overwrite the layout you set up for your project.