This got folded up into GTK+ years back as the GTK Inspector, so we dropped further development on it. They could do more with this being part of GTK+ than we could as a loadable module.
I also don't really work on GTK-based applications anymore, so it didn't make sense to continue development when I no longer had a vested interest in building new features for it. Instead, I build Review Board (https://www.reviewboard.org -- code review product) full-time now. Takes about 156% of my time.
The little Parasite bug lives on, though, as the mascot for Splat, a bug tracker we maintain for our needs (and might turn into a product someday). See https://hellosplat.com/tour/ for more drawings of the little guy.
Which reminds me, I filed a security bug years ago against it (using the mentioned Splat), and no one seems to have ever noticed/looked at it.
#4614 if you're interested
We discussed it internally, but those discussions never moved to the bug. I'll follow up on there, give you an overview of why you saw the behavior you did and our rationale.
Thanks for the poke!
I used gtkparasite almost 10 years ago when I was learning GTK+, was quite useful :)
Took your suggestion and updated the webpage!
You can't do much more than changing the theme though, as Chrome window is managed mostly by its own rendering engine.
You can also make it run in Chrome, via GTK Broadway https://developer.gnome.org/gtk3/stable/gtk-broadway.html
GTK_DEBUG=interactive GDK_BACKEND=broadway BROADWAY_DISPLAY=:5 gnome-calculator
You cannot make Chrome render in Chrome this way, though, as it complains about lack of X display available.
"You can attach it to Chrome: https://imgur.com/n8Mf7J3
You can't do much more than changing the theme though, as Chrome window is managed mostly by its own rendering engine."