<p> <a href="http://oe.osa.org/virtual_issue.cfm?vid=36">Focus Serial: Frontiers of Nonlinear Optics</a> </p>Chalcogenide glasses offer large ultrafast third-order nonlinearities, low two-photon absorption and the absence of free carrier absorption in a photosensitive medium. This unique combination of properties is nearly ideal for all-optical signal processing devices. In this paper we review the key properties of these materials, outline progress in the field and focus on several recent highlights: high quality gratings, signal regeneration, pulse compression and wavelength conversion.