integrit is an alternative to file integrity verification programs like tripwire and aide. It helps you determine whether an intruder has modified a computer system. integrit's major advantages are a small memory footprint and simplicity. It works by creating a database that is a snapshot of the most essential parts of your computer system. You put the database somewhere safe, and you can then use it to make sure that no one has made any illicit modifications to the computer system. In the case of a break in, you know exactly which files have been modified, added, or removed.
Hogwash is a layer 2 packet scrubber based on the snort signature engine. Hogwash sits in line, and drops packets based on signature matches. The rule set will be familiar to anyone that has used snort before. Hogwash supports passive host identification and adaptive rule sets for added accuracy.