Very nice, clean interface.

One suggestion: you could make the text box smooth scrolling using a PGraphics2 to render the text and then copying the PGraphics2 using copy or pixels

Example:
void setup(){
}

void draw(){
 background(255,0,0);
 PGraphics2 oot=new PGraphics2(128,128,null);
 oot.beginFrame();  //begin the frame
 //oot.textFont(myFont,12);  //that's how you do text
 //oot.text("Heya!",20,20);
 oot.rect(20,20,70,30);  //draw something
 oot.endFrame();  //end the frame
 oot.loadPixels();  //load the pixels array
 PImage tmp=new PImage(oot.pixels, oot.width, oot.height, RGB); //copy into a temporary image
 copy(tmp,mouseX,mouseY,32,32,mouseX,mouseY,32,32);
}

Das Applet funktioniert leider nicht Folgende Exception wird geworfen:

Laden: Klasse Imagine nicht gefunden
java.lang.ClassNotFoundException: Imagine

at sun.applet.AppletClassLoader.findClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

at sun.applet.AppletClassLoader.loadClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

at sun.applet.AppletClassLoader.loadCode(Unknown Source)

at sun.applet.AppletPanel.createApplet(Unknown Source)

at sun.plugin.AppletViewer.createApplet(Unknown Source)

at sun.applet.AppletPanel.runLoader(Unknown Source)

at sun.applet.AppletPanel.run(Unknown Source)

at java.lang.Thread.run(Unknown Source)
Caused by: java.io.IOException: open HTTP connection failed.

at sun.applet.AppletClassLoader.getBytes(Unknown Source)

at sun.applet.AppletClassLoader.access$100(Unknown Source)

at sun.applet.AppletClassLoader$1.run(Unknown Source)

at java.security.AccessController.doPrivileged(Native Method)

... 10 more
Exception in thread "Thread-4" java.lang.NullPointerException

at sun.plugin.util.GrayBoxPainter.showLoadingError(Unknown Source)

at sun.plugin.AppletViewer.showAppletException(Unknown Source)

at sun.applet.AppletPanel.runLoader(Unknown Source)

at sun.applet.AppletPanel.run(Unknown Source)

at java.lang.Thread.run(Unknown Source)
java.lang.NullPointerException

at sun.plugin.util.GrayBoxPainter.showLoadingError(Unknown Source)

at sun.plugin.AppletViewer.showAppletStatus(Unknown Source)

at sun.applet.AppletPanel.run(Unknown Source)

at java.lang.Thread.run(Unknown Source)