The talk considers usage of eye trackers to track usability issues in FLOSS. The use of consumer-grade hardware eye trackers is considered for cases when there is an SDK for Linux available, and when there is not. A webcam-based software eye tracking approach is considered as well and compared with hardware eye tracking using illustrative examples. Visualization of short-term and long-term eye tracking data series is explained with sample code for Graphviz and GNU Octave. Examples of eye tracking heatmaps and their usage scenarios are discussed, as well as using mouse heatmaps as supplementary data.