What are some alternatives?
When comparing GIMP and Adobe Photoshop, you can also consider the following products
Krita - Krita is a professional FREE and open source painting program. It is made by artists that want to seaffordable art tools for everyone. Concept art. texture and matte painters, illustrations and comics.
Affinity Photo - Affinity is the imaging and design suite for creative professionals exclusively for Mac.
Pixelmator - Pixelmator is an image-editing application for Mac and iPad.
Pixlr - Pixlr® makes it easy to transform everyday images into stunning works of art.
Sketch - Professional digital design for Mac.
Paint.NET - Paint.NET is a free image and photo editing software.