FileTraq is a shell script designed to be run periodically from the root crontab. Each time, it compares a list of system files with the copies that it keeps. Any changes are reported in diff or patchfile style, and dated backup copies are kept. It lets you keep an eye on intruders who might change system files, or other sysadmins who don't tell you about changes. It even helps you keep track of your own changes, along with dated backups.
The Fink project wants to bring the full world of Unix Open Source software to Darwin and Mac OS X. It modifies Unix software so that it compiles and runs on Mac OS X and makes it available for download as a coherent distribution. Fink uses Debian tools like dpkg and apt-get to provide powerful binary package management. You can choose whether you want to download precompiled binary packages or build everything from source.
Firewall Builder consists of a GUI and set of policy compilers for various firewall platforms. It helps users maintain a database of objects and allows policy editing using simple drag-and-drop operations. The GUI and policy compilers are completely independent, which provides for a consistent abstract model and the same GUI for different firewall platforms. It currently supports iptables, ipfilter, ipfw, OpenBSD pf, Cisco PIX and FWSM, and Cisco routers access lists.