Cacti is a complete frontend to RRDTool. It stores all of the necessary information to create graphs and populate them with data in a MySQL database. The frontend is completely PHP driven. Along with being able to maintain graphs, data sources, and round robin archives in a database, Cacti also handles the data gathering. There is SNMP support for those used to creating traffic graphs with MRTG.
wavemon is a ncurses-based monitor for wireless devices. It allows you to watch the signal and noise levels, packet statistics, device configuration, and network parameters of your wireless network hardware. It has currently only been tested with the Lucent Orinoco series of cards, although it should work (with varying features) with all devices supported by the wireless kernel extensions written by Jean Tourrilhes.
sslh accepts connections in HTTP, HTTPS, SSH, OpenVPN, tinc, XMPP, or any other protocol that can be tested using a regular expression, on the same port. This makes it possible to connect to any of these servers on port 443 (e.g. from inside corporate firewalls, which almost never block port 443) while still serving HTTPS on that port. sslh supports IPv6, privilege dropping, transparent proxying, and much more.
PacketFence is a fully supported, trusted network access control (NAC) system. It includes a captive portal for registration and remediation, centralized wired and wireless management, 802.1X support, layer-2 isolation of problematic devices, and integration with the Snort IDS and the Nessus vulnerability scanner. It can be used to effectively secure networks, from small to very large heterogeneous networks.
nrun is a tool that runs a single command or script on multiple target servers synchronously. ncopy will copy a file or directory to multiple target servers. The underlying remote access mechanism is interchangeable, and currently supports ssh, nsh, rsh, and local execution modes. The return code and all command output is logged.
SMCRoute is a daemon and command line tool to manipulate the multicast routes of the Linux kernel. It can be used as an alternative to dynamic multicast routers like 'mrouted' in situations where (only) static multicast routes should be maintained and/or no proper IGMP signaling exists.