RawTherapee (64-bit) v5.8

RawTherapee is a free and open source RAW image processor to edit RAW formats from most digital cameras and DSLRs with advanced controls for exposure and color adjustments, sharpening, denoising, color management, white balance, color channels, and much more.

The program also supports cropping and resizing as well as corrections for vignetting, distortions and perspective.
RawTherapee keeps track of all your editing actions and allows you to switch back and forth between different versions of the image. You can save your adjustment settings as profiles and quickly apply them to similar images. Other features include customizable interface layouts and full-screen mode, multiple denoising methods, dual monitor support, batch processing, support for color profiles and more.

RawTherapee can be quite memory intensive during RAW conversion and is optimized for 64-bit operating systems.