userv is a security boundary tool written by Ian Jackson for management
of User Services. It consists of a client and a daemon, with the client
asking the daemon to execute the service.

It can be used for such things as a cron which didn't have to be run as
root, or mail delivery with sophistcated filtering rules as defined by
the user, or cgi scripts which only affect the user who owns the script.

http://www.chiark.greenend.org.uk/~ian/userv/

-- Matthew Byng-Maddick <mbm@colondot.net>
