elfrc is a program which can turn arbitrary files into ELF object files which can then be linked into your program directly and accessed via simple, user-defined symbol names. Since this is much more effective than turning a binary file into a C array and then compiling that, it's possible to embed even huge (a few hundred megabytes) files directly into the executable and then access the data in constant time without making the compiler or linker eat loads of memory.
FreeBSDShield is a DShield.org reporting client for FreeBSD and the ipfw firewall. It allows you to report attempted security breaches to the DShield cooperative firewall logging effort, which in turn helps the Internet Storm Center (and netizens at large) track trends in network security and catch emerging vulnerabilities.
EmSniff is an application that helps you to capture network packets. It differs from TCPDump in that it runs as a service instead of an application. This makes it possible to capture packets in the background. This can help applications like Wireshark to be more secure since they don't have to run with root privileges anymore. They only have to connect to the EmSniff server via libemsniff.
This daemon makes GVRP announcements of all VLAN interfaces on a FreeBSD system. GVRP is the GARP VLAN Registration Protocol, defined in IEEE 802.1Q (VLANS). GARP is the Generic Attribute Registration Protocol, defined in 802.1D (bridging). The protocol allows switches or trunked end stations to announce to the network what VLANs should be forwarded to that device. The effect is that VLANs only need to be configured on the member ports; the protocol figures out which trunk ports are effectively also members. The daemon just announces the VLANs statically configured on each interface to that interface. It does not listen for inbound GVRP announcements.