Although no longer affiliated with UCB, Keith Bostic continues
to maintain, enhance, and distribute nvi.
The version current at the time of this writing is
nvi 1.79.
nvi is important because it is the
"official" Berkeley version of vi.
It is part of 4.4BSD-Lite II,
and is the vi version used on the various popular
BSD variants such as NetBSD and FreeBSD.