The XE Toolkit is a multi-platform, network-aware, secure performance monitoring solution for tactical analysis of enterprise computing systems. It uses Java and provides an API in the form of Java jar files that contain the programmatic interfaces needed to craft custom tools. It remains a toolkit, perhaps more complex than the SE Toolkit, but also far more versatile.
Zenoss is an enterprise network/systems management application that provides an integrated software package for monitoring availability, performance, events, and configuration across layers (network, servers, applications, environment, etc.) and across platforms (Linux, Windows, Unix, etc.).
aircrack-ng is a set of tools for auditing wireless networks. It's an enhanced/reborn version of aircrack. It consists of airodump (an 802.11 packet capture program), aireplay (an 802.11 packet injection program), aircrack (static WEP and WPA-PSK cracking), airdecap (decrypts WEP/WPA capture files), and some tools to handle capture files (merge, convert, etc.).
fupids2 is a so-called human oriented IDS based on the FUPIDS project. fupids2 calculates an attacker level for every user on all Unix/Linux/BSD systems in the network. It looks at the behavior of the user (the programs the user uses, the daytime the user is active, the building and room the user uses, the part of the room in which the user sits, and so on) and reports if the user engages in behavior that is unusual for that person. This method can often detect accounts overtaken by attackers.
Network Tracker and Management is a Web-based network management application. It can store information about all of your network devices, and allows you to track all changes and updates made to the device. Having this information readily available will enhance your ability to troubleshoot network problems.
mwcollect is an easy solution to collect worm-like malware in a non-native environment like FreeBSD or Linux. The first versions were used to collect binaries for botnet monitoring, and bots are still what it is mostly collecting. Some people consider it a next generation honeypot; however, that comparison often leads to the misunderstanding that computers running mwcollect can actually be infected with the malware, which is not the case.