We address the use of visualization and interactivity in molecular dyn
amics simulation. In an interactive environment the simulator is not o
nly provided with the means to view the system in alternative ways in
real-time, but is also able to 'steer' the computation in different di
rections by changing the governing parameters of the system. The simul
ational experience can be enhanced significantly by such means. Severa
l examples are outlined.