You can use the applet freely to enhance your web pages (commercial or non-commercial). However, I placed a status bar warning that will appear when the applet is online on a site and regcode parameter isn't correct.

 Author:   Gokhan Dagli
 Mail :   info@appletcollection.com
 Class File :   colorfader.class
 Registration Fee: $29 (You can download and test it.)