...It scans content for phrases, assigns a score to a page and will redirect to a block url for each page with a score that passes a pre-configured limit...
It's kinda like a spam filter for the web.
icappfd is used with proxy servers (squid3, and probably others) to protect users from certain types of content such as gambling, peer2peer, porn etc etc.
ClamCour is a Courier-MTA multithread filter that allows Courier to scan mail for viruses using Clam Antivirus package. Attachments can be "quarantinated" and custom domain-based email reports can be sent.