This has long been one of the strengths of Delphi – the strong collection of 3rd party components. 3rd party component development was of course fostered by the fact that Delphi came with full source for the VCL and RTL. A move the Microsoft if finally duplicating in releasing the source for the .NET framework. Although unlike Delphi, Microsoft will not allow you to modify and recompile the framework in your applications. With Delphi you can tweak the VCL and recompile it (not a trivial task, but allowable and possible) for your applications. Granted doing so makes moving to new versions of Delphi a little more tricky, and you cannot redistribute the modified source.

BTW, notice the link to my TurboPower page on line 27.