I think that Xkins can be used to achieve maximun flexibility in skinning a web application. I created Xkins for a customer in a finantial industry. It is a network of banks and each bank want their clients to use this web application but with each bank's look&feel and branding. This system is used by 20K users and Xkins is mature enought for this application (2 years of being used)
And I created some funny skins too, like the Simpsons Skin and Matrix Skin not to be so boring using this application in development
Besides Xkins can be used with
JSF (XkinsFaces) and I think that this is the next technology to be used in developing web applications.
Please, let me know If you have more questions or if you need a deeper explanation or something does not fit yoour needs.
Cheers.
Guillermo (gmeyer1604@hotmail.com)