I've been spending a little time on my attractor applet to improve it (and improvement was indeed direly needed). Now it's possible to reparameterize by holding left mouse button and moving the mouse. That will produce a live preview. Releasing the mouse once a desired shape is arrived at will render said shape using a large number of iterations.

Antialiasing is done using a logarithmic density map to control brightness and by fuzzing coordinates a bit using random(). I've still to implement blending of single pixels hit by more than one color to reduce the current flipping during rendering.