MirBSD originated as a patch set against OpenBSD-current, an ultra secure operating system and NetBSD derivate, and has since also incorporated changes from NetBSD, a 4.4BSD-derived ultra portable operating system. It features bugfixes, code removal for the sake of simplicity, and feature enhancements over stock OpenBSD as well as a much more up-to-date GNU toolchain, careful integration of patches from other projects (such as KAME), and many improvements. It works on the Intel Pentium and some 80486 machines with more than 32 MiB RAM and the SPARC, and a port to the PowerPC Macintosh is in preparation.
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.
dmassage uses the information in a BSD system's dmesg to gather information about the system's hardware devices and present this information in a tree-like hierarchy. This information can then be used to build a more efficient kernel that only contains support for devices that are actually present. It can also be used to disable probes for absent devices, thus speeding up the boot process.
flashboot for OpenBSD is a set of makefiles, scripts, and support tools to build an OpenBSD image suitable for booting from read-only media, such as flash memory. The default image (smaller than 5Mb) is an image for a firewall/router with support for IPsec, SSH, IPv4 and IPv6 packet filtering, DHCP (client and server), and PPPoE. This image may be further trimmed or extended by editing the packing list files included in the distribution.