GIMP 2.10 originally focused on porting the program to a new image processing engine, GEGL, but the new version also offers improved tools, better file formats support and a plethora of improvements targeted at digital painters and photographers.
GIMP is arguably the closest it gets to an open source free alternative to Adobe Photoshop. With tons of features and image manipulation tools at your disposal (and the complexity that comes with it), GIMP is a powerful cross-platform desktop photo editing program. The latest version brings several GUI improvements, bug fixes and general enhancements. Full release notes and download links for Windows, macOS and Linux are here.