Darren Reed is the author and software maintainer of IP Filter (commonly referred to as ipf) which is an open source software package that provides firewall services and network address translation (NAT) for UNIX-like operating systems. He got a fight with Theo de Raadt over something as inane as his license not allowing for OpenBSD to modify without authorization, and redistribute at will, thus sending Theo off the handle. Theo subsequently removed IPF, with no other tool available in its stead, and Darren had to create his own OpenBSD with IPF distribution.)