Heretic shareware?

What's a source port I can use for my heretic demo. Zdoom doesn't work.

Try Legacy or JHeretic, if you want. Oh and by the way, ZDoom will work with the Heretic shareware/demo, you just don't have the right version to play it with. I'd suggest v.1.23a and up.
ZDoom 1.22 doesn't support Heretic, shareware OR registered.