Pace-IDS is an Intrusion Detection system designed to replace Tripwire, in that it is faster, and more effective of detecting trojan activity, and is easier to configure. All you have to do usually is simply change one variable to your email address.
Pace Check is a utility that searches through system logs and finds cases where someone has tried to gain access to your server (non-legit), then it saves them to a log, mails them to you, or sends them to stdout. It supports http, ftp, and others.