A Makefile and set of shell scripts for turning a new OpenBSD box into a mail server with one command.
Ansible playbook for self-hosting your own email, web hosting, XMPP chat, and DNS records using OpenBSD. Used to host everything on c0ffee.net, but you can easily adapt it for your own domain by setting a few variables in vars.yml.
An impressive collection of research papers, exploits, and utilities.
An in-depth description of how pseudorandom number generators work (specifically, in Linux and OpenBSD) and how to improve the entropy pools of systems. Includes instructions on testing the entropy available, running an entropy gathering daemon to keep the entropy pool full, and how to rig up a wireless network interface to seed the kernel entropy pool.