While I have not tried to get get puppet working on HP-UX, I have gotten it to work on a number of other very old platforms by using ruby gems. If you can get a working puppet-supported version of ruby on HP-UX, you are most of the way there. Hopefully, you can get the ruby from a source that already compiled and packaged it, otherwise you'll have to compile ruby on your own, which isn't too bad if you have gnu tools from
http://hpux.connect.org.uk. Once you have ruby with gems support, the steps are basically:
* gem install --version <version you want, or leave out for the latest> puppet
* This will install 'puppet' and 'facter' within the case bin directory ruby is in
* Create /etc/puppet and /var/lib/puppet directories
* Add a working /etc/puppet/puppet.conf
* Run it as usual by hand: /your/path/bin/puppet agent -t
* Create a puppet init script and place into /sbin/init.d, with links to it in....whatever HP-UX uses
The benefit of this approach is you get the latest 'n greatest puppet version, and you can even use the package resource's gem provider (may need to sym-link /your/path/bin/gem to /usr/bin/gem') to update the gem in the future if you so desire to keep all puppet versions the same.