I will present two programs that facilitate computational exploration of reaction-diffusion patterns. The first program operates on a flat 2D grid and employs a graphical processing unit to simulate such patterns at interactive rates. The second program allows for simulation of reaction-diffusion processes on arbitrary triangulated surfaces. Parameter values and initial distributions of morphogens can be interactively “painted” on the domain to simulate non-homogeneous environments and different starting conditions. Experimentation with the models is facilitated by the use of a software versioning system, adapted to organize computational experiments and the models.