When they want to use GNU/Linux to manage a photographic work flow, most people are afraid that they would not be able to obtain a good color calibration for their monitor. This has long been an issue, but this is no longer the case thanks to the ArgyllCMS set of open source color calibration tools by Graeme W. Gill, for Linux / Windows / Mac OS X.
Unfortunately, ArgyllCMS is only a set of command line tools. So, they lack most of the pleasant interface that we photographers prefer to use.
This is no longer an issue when you start using dispcalGUI, a graphical front-end for several utilities from the open source color management system ArgyllCMS, specifically
dispwin, which when used together allow you to calibrate and profile your display using a measurement device.
No need to worry about command line commands and options!
GNOME: Gamut Mapping Options
GNOME: Edit Testchart
GNOME: Display Adjustment
GNOME: View Curves
Mac OS X
If you are a photographer and you use Linux, you cannot afford not to use dispcalGUI.