iSat: Structure Visualization for SAT Problems. We present iSat, a Python command line tool to analyze and find structure in propositional satisfiability problems. iSat offers an interactive shell to control propositional SAT solvers and generate graph representations of the internal structure of the search space explored by them for visualization, with the final aim of providing a unified environment for propositional solving experimentation. iSat was designed to enable simple integration of both new SAT solvers and new visualization graphs and statistics with a minimum of coding overhead.