A forms engine allows data sharing between customizable on-line forms, such as college admissions applications. Before applying, an applicant opens an account with a third party application servicer. After the applicant completes an application for one institution, the data is saved in a data base and automatically populates fields in subsequent application forms. The form for each institution is created from a form description file. Each form is branded for its institution and forms for different institutions differ in appearance and content so that the presence of the third party servicer is transparent to the applicant.The system is extensible without programming, allowing new applicant attributes to be readily incorporated into the system and allowing the content and appearance of the application to be readily changed by changing the description file. The use of aliases for applicant attributes permits data to be readily shared between forms even though labeled and arranged differently on different forms. Information stored about each attribute allows the specification of data validation rules and data sharing and grouping rules, as well as dependency rules that permit application page content to depend on applicant's responses on a previous page.