Darktable is a virtual lighttable and darkroom for photographers.
It manages your digital negatives in a database and lets you view them
through a zoomable lighttable.  It also enables you to develop raw images
and enhance them.  This project tries to fill the gap between the many
excellent existing free raw converters and image management tools (such
as ufraw or f-spot).

To run darktable, your processor must support SSE2 instructions
(i.e. Pentium 4 or higher, or Athlon 64 or higher).

The following are optional dependencies:

GraphicsMagick - for importing a wide range of non-RAW image formats
openjpeg - for exporting images in JPEG 2000 format
flickcurl - for exporting images to Flickr
json-glib - for exporting images to Facebook

If you have nVidia or AMD/ATI graphics with more than 1Gb of memory,
either nvidia-driver or amd-app-sdk is an optional runtime dependency.
Darktable will then detect and use the OpenCL capability of your graphics
hardware for faster processing.  See the Darktable User Manual, Chapter
7 Section 2, for more details (in particular, be sure to read it if you
have AMD/ATI graphics).