1. A computer-readable storage medium configured with data and with instructions that when executed by at least one processor causes the processor(s) to perform a process for implementing a web site, the process comprising the steps of: receiving an HTTP request which includes a path; mapping at least a portion of the path to locate an initial expression E in a nestable data structure which contains multiple expressions collectively representing the web site; evaluating the initial expression E thereby obtaining an initial result R, while avoiding evaluating other expressions of the nestable data structure; and then from the initial result R recursively mapping results to respective expressions by using mappings defined in the nestable data structure, and evaluating the respective expressions, until an evaluating step yields website content as a result R-final; and then generating an HTTP response to the HTTP request, the HTTP response containing the result R-final.