GPaR is a parallel graph rewriting software implemented in C++ with a graphical user interface. Considering an initial graph $g$ and a system of rewriting rules $R = \{l_i \to r_i; i = 1 \dots n\}$, GPaR rewrites the graph $g$ into a graph $g'$ by using, simultaneously, the rules of $R$ whose left-hand sides, $l_i$, match subgraphs of $g$. GPaR tackles the problem of overlapping matches and thus can be used in a large variety of rewriting problems including fractal systems. Our proposition is illustrated on the examples of adaptive mesh and Pythagorean tree. The performance of GPaR is compared to the performance of other tools on the Sierpinski triangle benchmark.