Fallback-gw is a little script to be called via cron that checks availibility of neighbor routers using ping and activates backup routing on ping failure. It can be used as a stupid replacement for BGP/OSPF in a multihomed environment. It has been tested on FreeBSD and on Linux with iproute2.
Lard is a Logging and Rotation Daemon that can replace the functionality of sysklogd and logrotate together. Logging is done almost exactly the same as syslogd, with added features such as regex matching and command triggers. Rotation can be triggered while the daemon is running safely by sending it a simple signal.
Nettion (NETwork TestIng and Operational eNvironment) is a framework for developing, deploying, and executing network performance tests, designed particularly for mobile ad-hoc networks. It is distinguished by not using control "backchannels" to start and stop the test, but rather using either a local setup network, the test network itself, or compact flash memory.
Nitpicker is an Ethernet accounting tool, which listens on an interface and accumulates all packets into flows. As it has been designed for *BSD's BPF, it also runs on Linux using libpcap. It writes raw file format flow files and has a dumping utility, and includes some tools for ISP billing.