[crazygringo]

This is a great move.

Serious question: how did this not happen 5 years ago? Is there some technical reason? It's so hard for me to understand why the creators wouldn't have always had this as the #1 feature improvement to make ASAP.

[armored_mammal]

I doubt most GIMP developers care(d?) about Mac. Or had Macs. Open source stuff tends to live in a special universe where everyone uses Linux.

(In fact, based on another post, it sounds like the windowing toolkit picked up Mac support, rather than Gimp doing anything super special.)

[fosap]

Also GIMP is in desperate need of manpower.

[wlesieutre]

There was Seashore, which was a simpler image editor based on GIMP, but native integration never seemed to be a priority for GIMP. I think there's a commonly held view on open source projects that they're all doing you a service, and if you don't like the tool they wrote you can fix it yourself or use something else. I can't say there's anything particularly wrong with that view, but it doesn't always lead to the greatest user experience.

I can only assume that someone (or several someones) with the time and knowhow to get this done finally came along and decided it was worth investing their time in. I doubt it's as exciting as working on the image editing features.

[Camillo]

A "native" version of GTK had been in the works for years, mainly supported by people who wanted to run other programs with it (CinePaint, I think). It seems that nobody had the interest in getting Gimp working with it, the skills to accomplish that, the time to dedicate to it, and the spirit of sacrifice needed to work on a GTK 2 port when GTK 3 is already out. But somehow, in the end, the stars aligned.