Swfdec is a decoder/renderer for Macromedia Flash animations. The decoding and rendering engine is

				// makeswf -v 7 -s 200x150 -r 1 -o addProperty-flags.swf addProperty-flags.as								trace ("Check if flags of variables get reset upon addProperty");								o = {};				o.addProperty ("foo", function () { trace ("get"); return 42; }, function () { trace ("set called"); });				trace ("set:");				o.foo = 20;				trace ("mark constant:");				ASSetPropFlags (o, "foo", 4);				o.foo = 20;				trace ("overwrite:");				o.addProperty ("foo", function () { trace ("get"); return 42; }, function () { trace ("set called"); });				o.foo = 20;								o.bar = 10;				ASSetPropFlags (o, "bar", 4);				trace (o.bar);				o.addProperty ("bar", function () { trace ("get"); return 42; }, function () { trace ("set called"); });								trace (o.bar);								loadMovie ("FSCommand:quit", "");