Abstract: A local runtime environment is loaded within a conventional web browser program and employed for generating a form based upon a definition that uses JavaScript or another data structure reversibly transformable into and out of JavaScript. The form can contain many pages, is generated locally, and its user interaction is handled by the local runtime environment without requiring interaction with a remote server from which the definition of the form may originally have been downloaded. The local runtime environment facilitates input and other user interaction with the form and executes any included functions. An almost unlimited variety of functions can be performed locally in connection with the form. Data that are input by a user can be saved locally or on a remote server. Optionally, an authorized user can enter a designer mode to make changes in the appearance and functionality of the form within the browser program display.