It's a private little war. Here's my unofficial and not-completely-informed analysis: As you know, the original ssh was developed with massive amounts of community input until the day when Tatu Ylonen decided to start selling it. The original scp protocol was based directly on the BSD rcp code. Tatu's ssh2 recognized that the over-the-wire protocol for ssh had to be an IETF standard, and so that is published. This permits the OpenSSH gang to implement the ssh2 protocol using the last free version of the original ssh. Therefore, for purposes of login, Finnish ssh2 and OpenSSH interoperate perfectly (or very nearly so, but I have reason to doubt about old Finnish ssh versions 2.0.x). However, for ssh2 the Finns re-engineered two very important other aspects -- the agent forwarding protocol and the scp protocol. The Finnish ssh2 version of scp is now based on some mechanisms which work well with Windoze, but this is not a published standard so the OpenSSH folks can't implement it without a clean room. Ditto for the agent forwarding. OpenSSH currently has a larger market share than Finnish ssh2. (Indeed, OpenSSH is now being bundled along with Solaris, HP/UX, and several other unixes.) At the risk of libel, I might suppose that the OpenSSH team is basically saying "Screw you, Tatu". Alas, the end result is that sites have to decide to use one or the other for purposes other than interactive logins. Furthermore, many of the authors of the IETF SECSH drafts are employees of the Finnish corporation. As soon as the SECSH drafts become RFCs, all the free ssh clones will undoubtedly implement the standard mechanisms. Given that this effectively destroys the Finnish business, there is not much incentive for the SECSH initiative to proceed quickly from draft to RFC. The process of getting full interoperability may take a long time.