BASE is the Basic Analysis and Security Engine. It is based on the code from the Analysis Console for Intrusion Databases (ACID) project. This application provides a web front-end to query and analyze the alerts coming from a SNORT IDS system.
Very basic RRDtool tutorial. It is an example in that way. It can save you a couple of days of discovering on your own. In any case you have to read the manual _before_ that ;)
secheck is a script which imitates currently existing log checkers but with a focus on security. secheck does some basic system security checking, then emails to output to a given user.