Everything I can find online about QtRuby uses Qt 4, but the current version of Qt is 5. Is this simply a matter of documentation not catching up with reality, where Qt 5 would work just fine with QtRuby?

If you assert that this is the case (that Qt5 is unsupported) then please backup your assertion with evidence.

QtRuby

Qtruby and korundum are not maintained for years now. To get a maintained version of qtruby, install qtbindings as ruby gem.

Qtbindings home page: https://github.com/ryanmelt/qtbindings/

Also see https://github.com/ryanmelt/qtbindings/issues/131 for a discussion about supporting Qt5.

Ruby-QML

Ruby-qml is a QML / Qt Quick wrapper for Ruby. It provides bindings between QML and Ruby and enables you to use Qt5 Quick-based GUI from Ruby.

The bindings provided by Ruby-QML are much leaner in comparison to QtRuby. In particular there is no direct access to the Qt classes' methods. That might first seem to be a a disadvantage when coming from QtRuby.

When learning to use use Ruby-QML, it turns out quickly that the advantages outweigh the limitations:

• QML and JS greatly complement to describe and model the static and dynamic aspects of the UI
• The user community of QML/JS is huge. It is so much easier to find examples or help to solve QML/JS issues, than it was within the tiny QT/Ruby community.
• The examples on Ruby-qml are pretty much complete to demonstrate the constructs needed to get started.
• JS may be used as flexible 'glue logic' between Ruby and Qt.