UDO is a powerful and multipurpose utility for
making documentation or any other text file that
is needed in one text format or more. Though UDO
is powerful, it's quite easy to understand and to use.
Parchive is a tool to apply the data-recovery
capability concepts of RAID-like systems to the
posting and recovery of multi-part archives on Usenet.
GNU grep, egrep and fgrep.
A Web filtering ICAP server for the Squid proxy server.