This guide contains instructions about installing Darktable 2.0, a free software for photography workflow, from PPA in Ubuntu 14.04. This PPA is official, provided by Darktable developer, Pascal de Bruijn. Thanks for him.
sudo apt-add-repository ppa:pmjdebruijn/darktable-release sudo apt-get update sudo apt-get install darktable
Note: in our system, it needs about 10.7 MB to download.