Argyll CMS is a popular open source display calibration, profiling and color management tool. Developer Florian Hoch has further harnessed the power of this utility by adding a graphical user interface, thus creating DisplayCAL. DisplayCAL allows the user to calibrate and characterise a range of display devices, with access to a variety of settings including customisable whitepoint, luminance and tone response curve - as well as support for look-up-table ICC profiles and optional gamut mapping. The tool also supports multi-display setups, and users are able to create custom test charts.