OpenSSH 5.4 Disables SSH Protocol 1
The new version of OpenSSH serves developers as a feature and bugfix release.
One new feature of OpenSSH 5.4 is that it disables SSH protocol 1 by default. Ten years transition from protocol 1 seemed enough for developers to disable it, although all SSH protocols are supported and protocol 1 can be explicitly enabled on the command line or in the configuration file if required.
The announcement lists all changes and bugfixes since OpenSSH 5.3. Being developed by the OpenBSD project, it is available in versions for Linux, Mac OS and Windows. Downloads are at openssh.com, with the mirrors for the portable Linux versions available in the meantime.