compiling on openbsd

I am attempting to install some tools (logcheck, etc)
on my openbsd boxes and have realized they are all
differant versions (2.8, 2.9, 3.0).

They are all firewalls of some sort, therefore I hate to
install all the development tools on each.

I have one 3.0 box with all the goodies on it just
for this type of stuff. Is there anyway to compile
for the previous versions on the 3.0 box?