Mostly donations. https://www.openbsdfoundation.org https://www.openbsdfoundation.org has some overviews. It's a fairly small project and doesn't have too many

Mostly donations. https://www.openbsdfoundation.org https://www.openbsdfoundation.org has some overviews. It's a fairly small project and doesn't have too many costs, relatively speaking. Previously the main income was from selling CD sets (they intentionally limited the web download options), but they stopped doing that about 15 years ago orso.