3.3 - Does OpenBSD provide an ISO image available for download?
In a word, no. The OpenBSD project does not make the ISO images used to master the official CDs available for download. The reason is simply that we would like you to buy the CD sets, helping fund the ongoing OpenBSD development. The official OpenBSD CD-ROM layout is copyright Theo de Raadt. Theo does not permit people to redistribute images of the official OpenBSD CDs. As an incentive for people to buy the CD set, some extras are included in the package as well (artwork, stickers etc).
Note that only the CD layout is copyrighted, OpenBSD itself is free. Nothing precludes someone else to just grab OpenBSD and make their own CD. If for some reason you want to download a CD image, try searching the mailing list archives for possible sources. Of course, any OpenBSD ISO images available on the Internet either violate Theo de Raadt's copyright or are not official images. The source of an unofficial image may or may not be trustworthy, it is up to you to determine this for yourself. We suggest that people who want to download OpenBSD for free use the FTP install option.
Bij deze, FTP install