  Visual layouts of graphs representing SAT instances can highlight the
community structure of SAT instances. The community structure of SAT instances
has been associated with both instance hardness and known clause quality
heuristics. Our tool SATViz visualizes CNF formulas using the variable
interaction graph and a force-directed layout algorithm. With SATViz, clause
proofs can be animated to continuously highlight variables that occur in a
moving window of recently learned clauses. If needed, SATViz can also create
new layouts of the variable interaction graph with the adjusted edge weights.
In this paper, we describe the structure and feature set of SATViz. We also
present some interesting visualizations created with SATViz.
