There are several differences between OpenBSD and Linux. These differences include but are not limited to, bootup procedure, network interface usage and disk management.
Most differences are well documented, but involve searching manpages.
This document tries to be an index of those differences. OpenBSD has a ports tree . This is to accommodate the fact that at this point not many applications are native to the OpenBSD environment. This is both an attempt to get applications to work on OpenBSD for end-users and to get more applications made with OpenBSD in mind. Eventually this ports tree will be used to make a nice set of binary packages.