1. A customizable application system comprising: an internet application system configured to support an internet application, the internet application associated with metadata configured for generating an a plurality of application user interfaces each having customizable interaction model, the internet application system including, a) an application server configured to generate the application user interface, and b) a web application server configured to deliver the application user interface to a client; a personalization system including a personalization engine and a user profile interface, the personalization interface configured to modify personalization data characterizing the interaction model such that the interaction model in more than one of the plurality of application user interfaces is modified; and a data repository including a data record for storing the personalization data, the data record being accessible using the metadata.