HTMLViewer - is it WKWebView or WebView internally?

Having a technical support conversation with Apple and they are asking me some questions about my use of Xojo HTMLViewers. Is it WKWebView or WebView internally? Has this changed at any point? Does 32/64 bit matter?

What version of Xojo did you use to compile your app ?

The app is currently built with 2014R2.1 but I’d like to move to the latest Xojo version if I can.

Xojo’s HTMLviewer uses WebKit.

For WebKit 2 with WKWebview, you can use our control here:

Xojo uses WebView because WKWebView wasn’t a capable enough replacement when it was first introduced.

When I see what broke in FileMaker with the switch, I would prefer to have an option there between WebView and WKWebView, if you guys change that someday.