gina2 helps you in archive and email automation. It provides a centralized email archive which is searchable by several criteria. You can also define actions that should happen when an email arrives.
rsscache allows you to aggregate and cache feeds (including RSS) into an SQL database and generate new feeds from them using search queries, categories, etc. A simple XSL example to turn the cache output into a new Web site is included.
GNU grep, egrep and fgrep.
A Web filtering ICAP server for the Squid proxy server.