Nobody mentioned the form inheritance feature of the VCL, the consequent applying of OOP principles for UI. Because all interface elements are implemented as (o

Nobody mentioned the form inheritance feature of the VCL, the consequent applying of OOP principles for UI. Because all interface elements are implemented as (object) components, in Delphi, you can easily group an arbitrary assembly of UI elements in a frame object and make it readily available as a new “component” for reuse; a great way to reuse standard design in big commercial applications. Another way of accelerating the production is to design similar screens as subclasses of a common screen. You can pack then all the common functionality in the ancestor screen and don’t waste time to copy-paste or worrying about error propagation. Of course, one can group common functionality in classes or procedures but UI functionality is very often bound to a certain UI element and not generic. Thus form inheritance is much more efficient than the (otherwise) standard practice. I designed once an application for museum management with a lot of different working screens but they are similar in some functionality. Using form inheritance I could avoid designing big generic working screens, which could be very confusing and annoying for the users, but offer instead specific screens for specific tasks and still saving a lot of time (and debugging headache). I estimate using form inheritance in Delphi helped me at the time to increase the productivity of the UI implementation phase up to the factor of 5! I guess other systems could do similar things but not as elegant as Delphi though. In term of desktop applications, I believe none other can be as productive as Delphi.