Flashlight is an open source process-tracing tool that records mouse movements in real time during an information search task (Schulte-Mecklenbeck, Murphy & Hutzler, 2011). Using this tool, acquisition behavior and visual attention can be recorded in an unobtrusive way with a wide variety of different stimuli. Because of the structure of the stimuli in Flashlight, information acquisition behavior can be measured similarly to how eye tracking works, but unlike eye tracking systems, Flashlight can be implemented without any special equipment. The motivation for developing a new process-tracing tool comes from experience with existing process tracing methods and their limitations. Other existing pro- cess tracing tools restrict the structure of information (often in a rigid matrix similar to an information board); require a fixed and confided laboratory setup; and need specialized hardware and software that is both expensive to purchase and operate. Flashlight solves these issues by providing a free open source adaptable software package that can work via a Web browser on any Internet connected personal com- puter. Moreover, the researcher has great flexibility in how stimuli are constructed and presented, and Flashlight also enables easy access to a large number of participants through Internet based experiments.