xwatch - 2.11-16.2 main

The displayed logs are colour-coded according to severity. Basically, you
get to see what's going on _during_ say a break-in, instead of having to
check the logfiles after the damage is done. Of course, you need to have
the syslog daemons configured right, so that the logfiles are
created. Xwatch reads options from its commandline as well as from a
app-defaults resource file.