Happiness for photographers out there. Lightzone v4 is a open source RAW converter and PP software. Looks like a mash up of Lightroom and Photoshop, it gives you layers control as well as many blending options. Do check it out.
http://www.dpreview.com/articles/5637768529/a-quick-review-of-the-lightzone-photo-editor
Download it here: http://www.lightzoneproject.org/
http://www.dpreview.com/articles/5637768529/a-quick-review-of-the-lightzone-photo-editor
Download it here: http://www.lightzoneproject.org/