http://www.techradar.com/news/the-best-free-alternative-to-adobe-lightroom

Adobe Photoshop Lightroom is the professional photographer's choice for processing raw images files, but it's not the only option. There are many great alternatives available completely free.

Lightroom has two main functions: processing images, and organizing them (through tags, naming, rating and other metadata). Like Lightroom, all the image editors we’ve featured here are capable of processing raw files straight from your camera.