The new handling of dockable forms replaces the workaround (with the red pin) by a more stable and platform independent procedure. All dockable forms are wrapped into a FloatHostSite, that adds an dock header instead of the form caption bar, which can be used to dock the client form on every platform. At the same time it becomes possible to dock multiple forms or other controls (toolbars, panels...) together, without any further coding.

If this approach will be accepted, some support should be added to the LCL, to simplify a stable integration of docking in general, and of persistent layouts in detail. Please see
http://dodi-lcl-dragging.blogspot.com/2010/04/docking-forms.html

I'll add another entry to that blog, considering docking-related LCL code that currently causes evitable flicker and further complications.

DoDi