In this webinar, we will introduce ParaView Catalyst, a flexible in situ library that leverages VTK and ParaView. The webinar will highlight the benefits of ParaView Catalyst and how to leverage them for your own simulations. ParaView Catalyst enables simulation codes to link to ParaView and VTK in order to perform in situ (i.e. while the simulation is running) the same type of work that is typically done in post-processing the results of a simulation run. Using ParaView Catalyst reduces the overall time to gleaning desired information from a simulation run. This is done by using the same compute power to calculate the desired quantities as the simulation has (for MPI-enabled simulation codes typically the post-processing is done on machines with much less compute power than the simulation ran on). This has the added benefit of reducing file IO while maintaining high fidelity in the quantities computed.