两个php写的爬虫程序

网上遇到的两个php写的爬虫程序，感觉不错，收集进来，一块瞅瞅：
sphider：（http://www.sphider.eu/）
Sphider is a popular open-source web spider and search engine. It includes an automated crawler, which can follow links found on a site, and an indexer which builds an index of all the search terms found in the pages. It is written in PHP and uses MySQL as its back end database (requires version 4 or above for both).
phpdig：（http://www.phpdig.net/）
PhpDig is a web spider and search engine written in PHP, using a MySQL database and flat file support. PhpDig builds a glossary with words found in indexed pages. On a search query, it displays a result page containing the search keys, ranked by occurrence.