TIM is a raytracer originally written to help with our research on METATOYs (see http://www.physics.gla.ac.uk/Optics/projects/METATOYs/) and its dissemination. TIM can be integrated into web pages (see, for example, http://www.physics.gla.ac.uk/Optics/play/TIM/), or run as a Java Application with additional capabilities (such as saving images).