I am currently in the process of writing a level editor for a 3D engine I am building. I am wondering as to the various ways to create editing windows for various views (top view, left view, front view, 3D view, etc). Some background...I''m not using MFC, just straight Win32 API calls. I tried making a system where there were a number of splitters, each with a left side and a right side, and on either side of the splitter there could be either another splitter or a window (I hope that kinda makes sense). I had problems getting view resizing to work. I also tried creating MDI child windows for each view, but that made the frame window very cluttered and it would also be difficult to organize the views that way, as you would have to line all the windows up by hand. So how do existing 3D editors do it, like WorldCraft? How does your 3D engine do it? I would like mine to be customizable, so that the user can set up the windows any way he or she wishes. Any help would be greatly appreciated.