This mini-course will introduce the participants to different approaches in tackling the task of parallel debugging, including the use of advanced parallel debuggers, such DDT. Overview: Debugging single processor code is already a daunting task that usually consumes a lot of development time. Luckily, many debugging tools are available to help the developer pinpoint the problem by controlling the state of execution. When dealing with large multi-processor code, however, this task becomes a true challenge for which the usual tools sometimes fail to provide a satisfactory solution when used exclusively. Dr. Stephane Ethier is a Computational Physicist in the Computational Plasma Physics Group at the Princeton Plasma Physics Laboratory (PPPL). He received a Ph.D. from the Department of Energy and Materials of the Institut National de la Recherche Scientifique (INRS) in Montreal, Canada. Please register online at the training website, www.princeton.edu/training or contact Andrea Rubinstein at firstname.lastname@example.org /258-1397.