How common are gear-driven or belt-driven superchargers in modern aircraft? How common are gear-driven superchargers in modern piston-engine aircraft, either alone or in combination with exhaust-driven turbochargers? What are some examples of modern aircraft that use them? Is it a technology that essentially went extinct in the aviation context with the last of the piston-engined fighters, bombers, and large airliners? Such that turbocharging alone (or other variants such as turbonormalizing) is the preferred technology for piston-engine aircraft now?  (Besides the old standby of normally aspirated engines of course.)

How about belt-driven superchargers-- do any aircraft have them?  If so, which ones?

Feel free to consider homebuilt aircraft, experimental aircraft, lightsport aircraft, and automotive conversion engines in your answer.

Edit: in light of a recent comment, I'll add that I'm asking about devices that are used at least in part to increase thrust and power by feeding pressurized air to the engine, rather than only to pressurize the cabin.
Lycoming offered mechanical superchargers in some of their large 6 and 8 cylinder opposed engines like the GSO-480 but such engines have been out of production a long time.

I would say the only mechanical superchargers to be found on any engines manufactured today would be found on Russian or similar Eastern European radial engines like the M14P.

I'd be pretty shocked to hear of a homebuilder incorporating a mechanical supercharger, but maybe somebody will find an example. In any case, if you're going to do it, so much easier to do it with a turbo.  The thing that makes turbocharging difficult to work seamlessly in cars, the power lag issue, isn't a problem with aircraft, so a turbo is a no-brainer that can be done by the homebuilder on just about any engine if they really want it.  To incorporate a mechanical drive system on an engine not designed for it would be quite a daunting task.