Most of IDE seems to be working acceptably on F19. But trying to open a file (e.g. html file) throws up error message:
"Could not open the Visual Page Editor:
No more handles [Browser style SWT.MOZILLA and Java system property org.eclipse.swt.browser.DefaultType=mozilla are not supported with GTK 3 as XULRunner is not ported for GTK 3 yet]
No more handles [Browser style SWT.MOZILLA and Java system property org.eclipse.swt.browser.DefaultType=mozilla are not supported with GTK 3 as XULRunner is not ported for GTK 3 yet]"

After clicking OK, the error message closes and the editor opens. Just the visual part of the visual/source tab shows an error message. But switching away to the source tab and then back to the visual/source tab causes the error message to be shown again.

I know we know there are Luna-Linux issues. But I'm reporting this here as it seems we weren't sure if Fedora 19 would be affected. Also JBIDE-16280 seems to report the issue as being resolved in 4.2.0.Alpha2 but I'm finding it isn't in Beta1.