Automatically creating and modifying a search engine for a website. User input may be received specifying an address of a website. A search engine may be automatically created for the website based on the user input. Webpages of the website may specify a plurality of tags specifying custom attributes of the webpages. During creation of the search engine, these custom attributes may be incorporated into the search engine index. Additional user input may be received customizing the search engine for various search engine contexts, e.g., based on the custom attributes of the webpages. Search engine results for the website may be based on various ranking functions, potentially including social impact of webpages of the website.