I’m not familiar with ports, does it provide an easy way to install packages of a particular version? Is it OpenBSD only, or just a system of installing things?
OpenBSD’s ports are just a collection of perl scripts and makefiles managed by a VCS (usually CVS though there are mirrors). Due to how recursive CVS works, you can easily update any part of the tree to a different commit/tag.
<span style="color:#323232;">$ cd ${PORTSROOT}/games/stone-soup
</span><span style="color:#323232;">$ cvs up -CPd -D </span><span style="color:#183691;">'some date_spec' </span><span style="font-style:italic;color:#969896;">#or -r some_tag
</span><span style="color:#323232;">$ make install
</span><span style="color:#323232;">$ヽ༼ຈل͜ຈ༽ﾉ enjoy your old or backported videos games
</span>
very scriptable, should be easy to figure out how to automate this should you need to.