  Reaction systems are a computational model inspired by the bio-chemical
reactions that happen inside biological cells. They have been and currently are
studied for their many nice theoretical properties. They are also a useful
modeling tool for biochemical systems, but in order to be able to employ them
effectively in the field the presence of efficient and widely available
simulators is essential. Here we explore three different algorithms and
implementations of the simulation, comparing them to the current state of the
art. We also show that we can obtain performances comparable to GPU-based
simulations on real-world systems by using a carefully tuned CPU-based
simulator.
