Also, a free version introduced a limit of 15 concurrent connections and a commercial version was offered for purchase.

Also, slightly unfair to compare apache & nginx when you are hitting them (in your example) with 200 concurrent connections.

That's limited to 10 IPs, 10 users, and a thousand concurrent connections.

"Non-blocking" means that other concurrent connections do not prevent connecting an arbitrary input to any arbitrary output.

Well, they've waived that subscription fee if you're ten users or ten IP addresses and up to a thousand concurrent connections.

Bluetooth with up to six concurrent connections (though only one can be a headset).

Only 10 concurrent file-sharing connections are allowed at any moment.

Multiple concurrent connections cannot be made with the same SRP ID.

Tabbed interface for multiple concurrent connections (Dockable)

For a home server with only three or four concurrent connections, it should work just fine.