Gradient.JPGcalc_circles.JPGCalc_Ellipse.JPGGraphs.JPGpacman.JPGhtends.JPGshaded.JPGDifferentiation.JPGExponential.JPGBlueofRed.JPGEllipseCalcday.JPG

Simply google Geogebra Calculus Applets and you will find heaps. for example:
http://webspace.ship.edu/msrenault/GeoGebraCalculus/GeoGebraCalculusApplets.html

Also See http://2011geogebralessons.wikispaces.com/Calc+Day+2011