Shotwell is a simple to use photo manager, designed specially for Linux systems (also for Windows with limited features) that allow you to manage and optimize your photo collections quickly.
You can import photos from folders or from any digital camera supported by gPhoto and automatically group photos taken at the same time. You can also use tags to organize your photo collection.
You can also rotate, crop, reduce red-eye, and adjust the exposure, saturation, tint, and temperature of each photo very quickly.
Besides, Shotwell lets you publish photos to Facebook, Flickr and Picasa Web Albums.
