It's been years since I worked in Delphi regularly, but I still have it installed and have been looking around in it this evening for the first time in a long while. Right now I can't find the option to change from this to a single-window mode, but I'm not sure there is one.
I think the trick is to just not run it maximized, then undock the various parts from the main editor window. Then once you have things resized and placed where you want, you save it as a Desktop layout. I don't know how far back that feature goes.
I would have to reinstall it from scratch somewhere to see how it looks by default. I really want to do this and dare say I even intend to! I may even have D5 and D3 somewhere in a box too, but now I'm approaching self-promise overload!!
Here it is maximized and docked. Is that something like what you remember?
it's a real blur but I do recall doing the unmaximize and undock stuff to get things looking just right. I distinctly recall no longer being able to do that in some version.. I thought it was 5 but you've proven me wrong. maybe D2005?
I'd say clearly Lazarus is tracking the best of Delphi, not just version 2 from 1995.