I prefer the multiwindow IDE myself, but you can make Lazarus single windowed. To do that go Packages -> Install/Uninstall Packages -> find the "anchordockingds

I prefer the multiwindow IDE myself, but you can make Lazarus single windowed. To do that go Packages -> Install/Uninstall Packages -> find the "anchordockingdsgn" package and install it (Lazarus is quite modular and packages can alter the IDE) by hitting the "Save and rebuild IDE" button. Note that this will have the form designer still as a floating window, if you want it to also be inside the IDE also install the "sparta_dockedformeditor". These aren't very obvious (in another comment i wrote that Lazarus can feel a bit messy and unpolished... this is one of the reasons i think that :-P) though and IMO it should be something that you get asked when you run Lazarus for the first time.