But see also what happened with Qt and its license issues. That didn't happen with Objective-C, but nobody could predict the future at the time. There are some

But see also what happened with Qt and its license issues. That didn't happen with Objective-C, but nobody could predict the future at the time. There are some advantages to controlling your stack. Also, pointing at GIMP's UI seems a little exaggerated, when the primary difficulty was keeping track of all the floating windows. GIMP seemed to have been designed in anticipation of a major advancement in window managers (not just tiling, but size-aware) that never materialized (the irregular packing problem is NP-Hard). Other Gtk apps never had this problem, and GIMP eventually switched to panes, thankfully.