Use Qt framework in their own QtCreator IDE.
Ranked in these QuestionsQuestion Ranking
Pro Visual GUI designer
QtCreator has QtDesigner component, allowing you to design a GUI in visual mode instead of raw code.
Pro Ready-made classes for most used tasks in desktop app development
Launching external applications, getting environment variables, putting tasks to separate threads, offscreen painting, transparent loading of most used image formats, even such helpers as opening files in default application configured in OS, cross-platform (!).
Pro Cross platform
Qt supports most popular platforms including Linux, FreeBSD, Windows, and Mac OS X. This allows developers to easily port applications to different platforms.
Con Vendor lock on QtCreator
It's not simple at all to use Qt in a different IDE, and you'll lose QtDesigner.