Pretty much all the apps were written in PHP on shared hosting. Since the system had support for a simple kind of forms (using GET requests), it was possible to

Pretty much all the apps were written in PHP on shared hosting. Since the system had support for a simple kind of forms (using GET requests), it was possible to accept queries for the various web apps. The search engine crawled the pages that existed looking for links from a few "start" pages, and built a primitive index.