Hi there everyone. After a lot of searching and lots of failures I come to Unity's Forums because I can't find a solution for this. What I'm trying to do is SIMPLY dock Two EditorWindows in one, side by side, just like you can do by simply dragging an editorwindow tab inside another editorwindow. There's some interesting old solutions I have been through, and the best is the following one:http://forum.unity3d.com/threads/docking-editor-windows-side-by-side-via-script.191437/ Unfortunately I can't seem to find the following classes: DockArea, SplitView, DropInfo. They were supposed to exist, but as they were internal classes at the end of 2013 I guess Unity's people just deleted them, because we can no longer use them. What I'm trying to accomplish is completely possible as seen in the following video: But the user who made it just didn't open source his scripts, so here I am, still trying to find a good solution on this. Again, I have tried lots of methods, also the well known EditorWindow.GetWindow(typeof(ParentWindow)); and this does not work like I want, it's only making tabs, not splitting the window in two in order to get space to both windows simultaneously.