The OpenBSD/sun3 port currently runs on all the 68020-based Sun3 computers, except the 3/E flavour.
The Sun3 port of OpenBSD was derived from the NetBSD/sun3 port, when the sun3 and sun3x ports were still different entities. The tiny bits of OpenBSD that are completely specific to the Sun3 port are basically the same as their NetBSD counterparts.
Supported devices:
There is no formal OpenBSD/sun3 release yet. Full snapshots, including userland, kernel, diskless and ufs bootstrap loaders are available.
The diskless configuration is prone to instability. If many processes coredump during multi-user startup, hit <L1-A> and from the ``>'' prompt use ``b le()bsd'' to reboot again. It usually works on the second try. Alternatively, you can boot single-user ``b le()bsd -s'', and exit single-user mode as soon as it appears with control-D. This behaviour doesn't appear when running from a local harddisk.
You can use cvs to get The X Window System. Kenneth Stailey had written patches for OpenBSD/sun3, which should have been intergrated into the mainstream XFree86 sources. However, X has not been tested on OpenBSD/sun3 for quite some time.
The Sun3 port of OpenBSD is maintained by Miodrag Vallat, miod@openbsd.org.