We propose a software architecture that uses existing standards to store and fetch the needed information to support client side customization in a way that the modified application is still available from any browser and any computer as it was the original one. This paper describes the proposed architecture and a prototype implementation as a proof of concept. A variety of user scripts were successfully tested on the prototype. Once properly configured, the customized application was accessed from different machines using different standard versions of the browsers. The customized application remains thus universally accessible and we do not need to loose this crucial advantage.