Lazarus on the FreePascal compiler does exactly that, borrowing from Delphi's heritage. It copies VB6 almost literally, in many ways, but can output binaries for win/mac/linux.

I've written a few toy apps in it and in my limited exploration it seems to be a joy to work with, once you get used to Pascal's quirks... and I'm not a fan of the ancient MDI workflow it imposes either.

I also learned to program with VB and Lazarus is the closest thing I've found. The WinForms designer in Visual Studio would be the next closest.

Both GTK and Swing have various GUI designers that are similar, but have their own design and use different layout metaphors. If you're looking for a more modern take on what's left of RAD maybe check them out.