NetApp, Dell-EMC Isilon, Juniper, iXsystems, pfSense, etc:

* https://en.wikipedia.org/wiki/List_of_products_based_on_Free...

If you follow the commit logs, you'll regularly see "Sponsored by" messages:

* https://www.freshsource.org/commits.php

Not just for the core OS, but also in ports and also drivers (Intel, Chelsio, Mellonox).

FreeBSD in particular has always been persnickety about acknowledging work done on behalf of others. Something that would have prevented the IBM-SCO lawsuit if Linux had used commit/patch tracking from the beggining.