TinyIB is a lightweight PHP image board which emulates the functionality of 4chan. If you use MySQL or SQLite, you can use it to create an efficient setup able to handle large amounts of traffic. If you don't use a database, it can store posts as text files for a portable setup capable of running on virtually any PHP host.
Btpd is a utility for sharing files over the BitTorrent network protocol. It runs in daemon mode, thus needing no controlling terminal or GUI. Instead, the daemon is controlled by the btcli command line utility or other programs capable of sending commands and queries on the btpd control socket.
flashrd creates OpenBSD images tailored for embedded hardware devices and for executing from a virtualized environment. It installs a complete OpenBSD system with "one-touch" upgrade capability. It boots from a ramdisk to make in-place upgrades easy and complete. flashrd partitions for read-only operation by default, to minimize flash wear.
SONaFR is a small system based upon OpenBSD 4.1 and 5.1. Version 1.0 is a floppy version with router, NAT, and firewall capabilities. No hard disk or CD-ROM is necessary. The system boots off a floppy, and all you have to do is to configure it. It also has transparent firewall and bandwidth control capabilities. Version 2.0 has two bootable USB images (OpenBSD 5.1); one has 120 MB, and the other one 1 GB. It has DHCP, Midnight Commander (a Norton Commander clone), and various basic system tools.