Delphi was designed to be COM-compatible, so the vtable layout was compatible, for example. Its interfaces, via the inbuilt interface keyword, use COM-compatible reference counting. It has inbuilt RTL types for handling a lot of common COM scenarios. It did this back in the 90s and remains extremely useful for COM still today.

Then late 2010s, C++Builder (its sister product) dropped ATL to DAX -- Delphi ActiveX aka COM -- and using COM from C++ uses the same inbuilt support, including keyword suggestions and RTL types. It's not quite as clean since it uses language bridging to do so, but it's still a lot nicer than normal C++ and COM.

Seeing someone do COM from first principles in 2025 is jarring.

You mean, like Microsoft themselves?

.NET COM support was never as nice, with the RCW/CCW layer, now they have redoned it for modern .NET Core, still you need some knowledge how to use it from C++ to fully master it.

Then there is CsWinRT, which is supposed to be the runtime portion of .NET Native, which to this day has enough bugs and not as easy to use as it was .NET Native.

Finally, on the C++ side it has been a wasteland of frameworks, since MFC there have been multiple attempts, and when they finally had something close to C++ Builder with C++/CX, an internal team managed to sell to their managers the idea to kill C++/CX and replace it with C++/WinRT.

Nowadays C++/WinRT is sold as the way to do COM and WinRT, it is actually in maintenance, stuck in C++17, those folks moved on to the windows-rs project mentioned on the article, and the usuability story sucks.

Editing IDL files without any kind of code completion or syntax highlighting, non-existing tooling since COM was introduced, manually merging the generated C++ code into the ongoing project.

To complement your last sentence, seeing Microsoft employees push COM from first principles in 2025 is jarring.

Oh I see. Python, Ruby, and various other high level languages, including of course the MS languages, have pretty seamless integration as well, although not at the level of direct binary compatibility. I imagine they just use wrappers.