Last time I used a QtWebKit browser, I could get around this easily by user agent spoofing. Not sure if the experience was totally perfect, but there were no glaring problems.
Doesn't change the fact that it's been deprecated/removed upstream, though, unfortunately.
It was used by KDE for some oauth workflows, where changing the user agent string was not possible, and auth consequently impossible. They've switched to the external browser instead.
Who outside of Apple is using WebKit at this point? And how often do the tarballs drop?
> Who outside of Apple is using WebKit at this point?
Gnome/GTK, at least. The one bundled with Gnome (previously called Epiphany) still uses it. I was going to say Midori, but apparently it's recently-ish switched to Electron, which is understandable, but a little disappointing.
There are other niche browsers using WebKitGTK, but with the loss of Midori (?) and Qt's WebKit interface its definitely got a really small presence now.
> And how often do the tarballs drop?
Unlike most open source projects inside Apple, WebKit is developed basically in the open, with a dedicated website at https://webkit.org/ and an SVN repo at https://svn.webkit.org/repository/webkit/. They also link directly to the WebKitGTK project, and provide instructions for building for/on Linux (and Windows).
It's kind of a shame it's not more widely used -- I understand why most people so inclined would prefer Gecko/Firefox, but there may come a time when the only valid choices are a rendering engine backed by Google's dollars, or one by Apple's dollars. And unlike Mozilla, which is still mostly relying on Google's dollars, Apple has a vested financial interest in keeping a separate and at least adequate web stack.
Edit: Worth mentioning one problem with WebKitGTK adoption in linux has been API deprecation. I haven't done any dev work with it, but I know a lot of projects just gave up after the WebKit -> WebKit2 port, and GTK itself can be a PITA. The tooling outside Darwin/OS X is more cumbersome, too.
JavaScriptCore is easier to embed/better documented than SpiderMonkey, though (IMO). And it can even run headless, although getting it to build headless can be, uh, finicky...