Nearly 5 years ago, I wrote an ink recognition demo and placed it on CodeCentral. It was only recently that it was brought to my attention that someone finally tried using my demo and have fun with it recognizing Chinese!
In 2017, with the release of Delphi 10.2 Tokyo, Embarcadero introduced a specialized implementation of the Observer pattern into the System.Classes unit. While it has been in the wild for 9 years, it remains a "hidden" architecture for many, primarily because it serves as the invisible engine behind LiveBindings. Other than live bindings, you can also use the Observer pattern as a way to update component settings to the Windows registry, an .ini file, or persist it elsewhere.
System.Classes