“darktable” is an open source photography workflow application and RAW developer. A virtual light-table and darkroom for photographers. It manages your digital negatives in a database, lets you view them through a zoomable light-table and enables you to develop raw images and enhance them. “darktable” is very similar to Adobe Lightroom but far less expensive at $0. darktable is availible for Mac and Linux. Windows users use run Linux as a virtual machine or dual-boot.

Have a look at its features and how to install it on your system.