virtual paper cut and fold snowflake simulation
This little exercise in interactive geometry was started as a flash "movie" written in ActionScript in 2002. But flash was really designed for animating sprites, and not for handling scripted primitive drawing commands (lines and polygons). So the java applet version was born, and development on that continued for a couple of years, during which time many features got added, including a gallery where you could save snowflakes for others to see, and even download a pdf version of your snowflake.
Over the years, applet technology has become even less widespread and more finicky, and we finally have a decent alternative to applets for interactive animation on the web: html5 canvas. So now in 2013 it seemed maybe the time had come to rejuvenate cutfold. The current incarnation is a port to javascript and canvas.
The basics (folding) is now working, but there is still some work needed to wire up cut and unfold.
You can fold the paper by (clicking fold and) dragging a line segment across it. Then clicking on one side or the other of your fold will push that side down, executing the fold.
You can cut the paper by (clicking cut and) drawing a series of connected lines by repeatedly clicking and moving the mouse; the cutting is finalized with a double-click (or by crossing your own cutting line).
You can discard pieces of paper. Be careful where you click: There is only one level of undo.
You can unfold - this unfolds the most recent fold, and can be repeated until the paper is completely flat.