If you're using Kylix 3, like I am, then you'll be happy to know that the “Unofficial VisualCLX patches 3.3” has been published 2-3 days back.
More information about what has been patched can be read here.
The homepage for Unofficial VisualCLX patches is here.
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