Could be that you have to sign the applet?

tried two other libraries and it works fine - somethings up with "ani"

Whether your browser security "allows all java" is irrelevant to the signed applet issue; it's down to cross-domain access from within an applet (see this tutorial).  However looking at the library I'm not so sure it would be likely to throw an AccessControlException.  The other thing to check is that the library actually got properly embedded in your jar...

OK - thought I might as well download the library and see what this was doing for myself.  The Java console is throwing the following error:

java.security.AccessControlException: access denied (java.lang.reflect.ReflectPermission suppressAccessChecks)

Looks like the library is doing some clever stuff in the background to deal with callbacks and this is what triggers the security alert.  So the solution is almost certainly as I originally suggested: you need to sign the applet.

When you run the applet in the browser a java icon should appear in the taskbar.
Right-click it and choose 'open console' ;)
You can also set preferences in the Java Control Panel so it always appears, but I reckon that might get annoying very quickly.

Actually you're right: Signing an applet does appear rather more complex than I expected (I've never had to sign an applet before).  The wiki tutorial doesn't help that much as it makes assumptions about your level of knowledge (e.g. how to use a 'terminal program', or even what one might be) and doesn't really explain what the commands you're inputting do...  It's probably fine for people who are used to working on the command line, but I - and I imagine many others using Processing - don't fall into that category.

I don't have time right now, but might hopefully get a chance to write a more thorough tutorial in the next couple of days...  That is assuming I can get my head round it :/

Animation library for timeline/keyframe based tweens and more: www.ekeneijeoma.com/processing/motionlib/

Just pust public infront of setup and draw and it will work.

1. /**
    * shows the basic use of Ani aka a Hello Ani
    * 	 
    * MOUSE
    * click           : set end position of animation
    */
   
   import de.looksgood.ani.*;
   
     float x = 256;
     float y = 256;
   
   public void setup() {
     size(512,512);
     smooth();
     noStroke();
   
     // you have to call always Ani.init() first!
     Ani.init(this);
   }
   
   public void draw() {
     background(255);
     fill(0);
     ellipse(x,y,120,120);
   }
   
   void mouseReleased() {
       // animate the variables x and y in 1.5 sec to mouse click position
       Ani.to(this, 1.5, "x", mouseX);
       Ani.to(this, 1.5, "y", mouseY);
   }
   
   
   

Have you managed to get the console to show up? (it is unrelated to the browser, BTW) Any new message there?

Looking closer at the pointed sketch, I think Cedric was close: that's x and y you have to make public, probably. Ie., in general, any variable or function whose name you pass to the library in string form.
The security issue here is because the library uses reflection to access the variables or functions, ie. accesses them using low level stuff that can be used to tamper with legitimate applications (bypassing normal access restrictions).