Comment 17 for bug 1297688

https://lwn.net/Articles/607563/ ("Shifting toward Qt") focuses only on GTK+ and Qt, rather than the other alternatives suggested in this bug, but between them concludes that:

"Nonetheless, it appears that, for the most part, there is growing technical frustration in the broader open-source community with GTK+; Qt seems to be gaining at least in part at GTK+'s expense. Portability, ease of development and reduced concerns about ABI breakage are some of the technical reasons expressed by many developers for choosing Qt over GTK+. It is far too soon to proclaim that Qt has achieved any sort of victory over GTK+, but Qt does appear to have the wind at its back at the moment."