Search engine: Google Co-op Clone

I need a clone of Google Co-op (see [login to view URL]) It should have a very good search algorithm and a fast spider to index any site I added into the search database. Some of the obvious features will be: - it can index unlimited webpages and websites - once indexed, the spider will frequently visit the specific website so to fetch the latest updated results - visitors can submit their own website to be indexed - it will spider the exact domain I added (i.e. if I add [login to view URL] it wont go and index the whole [login to view URL], only all pages under [login to view URL]) - highlighted or bold keywords searched on results pages - ability to add/edit/delete websites from the database - can index both static and dynamic pages, pdf and doc files - etc... It will be a long list if I'm to specify all the features, please take a look on the Google Co-op page for better understanding. The search engine is not meant to index everything on the web, its intended only to include all websites within a state or a district. But still it must have the abilities to index unlimited websites, has good results relevance and also retain fast searching speed even if the database get too large. Basically a clone of Google Co-op. It can be written in any languages as long as it met all the characters & functionalities. I would prefer to see a working demo