Firewalls became an indispensable part of computer networks. Corporations buy commercial firewalls or use open source firewall software packages to meet their need. Most of these are Linux or FreeBSD based and few of them are OpenBSD based, which has few features or are command line tools. In this project, creating an OpenBSD based firewall software package, which has a graphical user interface, an extensible infrastructure and targets embedded systems, has been aimed.Firstly firewall has been described and then previous studies about firewall software packages have been discussed. Since this study aims OpenBSD operating system and embedded hardware, the basics of OpenBSD and the design decisions for an embedded system have been discussed. Finally the infrastructure of the implementation of this study has been explained.