http://www.openp2p.com/pub/q/p2p_category
http://www.business2.com/webfile/0,1638,8782,00.html
http://www.bsoftware.com/directory.html
http://www.human-links.com/
http://open-content.net/
Grub provides a free for download, free to run, distributed crawling client, which is used to create an infrastructure (database + volunteers) that will eventually provide URL update status information for nearly every web page on the Internet. Grub’s distributed crawler network will enable websites, content providers, and individuals to notify others that changes have occurred in their content, all in real time.
http://grub.org/