OpenBSD does great work, but for the record OpenSSH started as a fork of the free SSH program developed by Tatu Ylönen; later versions of Ylönen's SSH were proprietary software offered by SSH Communications Security.
Since nobody uses protocol 1 anymore, very little of the original code from Tatu Ylönen remains in operation with default settings.
ps I have had to use the SSH commercial release under VMS, and the compatibilities with OpenSSH are quite unpleasant.