Need a TN3270 emulator, but are tired of waiting for a native app (or waiting for Classic to launch) while an impatient operator/user sits on the line? I use XDarwin (rootless), OroborOSX, and x3270. Read the rest of the article for the how-to...
After you've installed XDarwin and your window manager, get the x3270 sources.
Extract them and make the following changes:
% diff x3270-3.1.1-orig/Imakefile x3270-3.1.1/ImakefileFollow the build instructions (as detailed in the build docs) and make install it. I use the ibmhosts at /usr/X11R6/lib/X11/x3270/ibm_hosts. Set up .x3270pro in your home directory; I use [at least in part]:
107c107
< $(BINDIR)/$(MKFONTDIR) $(DESTDIR)$(FONTINSTDIR)
---
> $(MKFONTDIR) $(DESTDIR)$(FONTINSTDIR)
% diff x3270-3.1.1-orig/popups.c x3270-3.1.1/popups.c
502c502
< #if !defined(__FreeBSD__)
---
> #if !defined(__FreeBSD__) && !defined(__DARWIN__)
% diff x3270-3.1.1-orig/util.c x3270-3.1.1/util.c
589c589
< #if !defined(__FreeBSD__)
---
> #if !defined(__FreeBSD__) && !defined(__DARWIN__)
! modelfor 43 lines and you're good to go.
x3270.model: 3279-4-E
! name to transmit
x3270.termName: IBM-3278-4-E
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020401234815728