Installing windows version & Buffy on a Mac

[Sengir]

Install macports ( https://trac.macports.org/wiki/InstallingMacPorts ) (Xcode is installable through the App store nowadays).

Install wine & cabextract through Macports by running the following commands in a terminal

sudo port install wine
sudo port install cabextract

Still in a terminal, move to the directory where wine got installed and use winetricks to install a bunch of libraries

sh winetricks corefonts directx9 msxml3

If you run the game and you get errors about directx you can try the following

Spoiler :

sh winetricks d3dx9 d3dx9_26 d3dx9_28 d3dx9_31 d3dx9_35 d3dx9_36

If that doesn't work either, you can copy and overwrite EXACTLY the following dynamic link libraries to wines windows/system32 directory:
d3dx9_26.dll d3dx9_31.dll d3dx9_32.dll d3dx9_33.dll d3dx9_34.dll
If you have a windows box, you can copy them from there, otherwise they can be found online.

If you get errors relating to xml:

Spoiler :

Copy and overwrite EXACTLY the following dynamic link libraries to wines windows/system32 directory:
msxml3.dll msxml3r.dll
If you have a windows box, you can copy them from there, otherwise they can be found online.

run winecfg from a terminal

winecfg

Set windows version to XP
Go to the tab Libraries
Add new overrides (native) for msxml3, d3dx9_26, d3dx9_31, d3dx9_36
Go to the tab Graphics
Make sure to check 'Emulate a virtual desktop' (I couldn't get it to work decently otherwise, might be different under Lion though as it has better support for fullscreen apps); pick a resolution to you liking.
I went to stations and added my download folder as a station to make it easier to find my save files.

Now onto installing Civ4
Insert the CD/DVD (I have Civ4Complete so I only had one installer to run).
Using the terminal, navigate to the CD/DVD (cd /Volumes/CIV4_COMPLETE/ in my case)
Run the installer

wine setup.exe

Download the 3.19 patch and navigate to it using the terminal
Install the patch

wine Civ4BeyondTheSwordPatch3.19.exe

Download Buffy and navigate to it using the terminal; install it

wine BUFFY-3.19.003.exe

Run the program

wine ~/.wine/drive_c/Program\ Files/2K\ Games/Firaxis\ Games/Sid\ Meier\'s\ Civilization\ 4\ Complete/Beyond\ the\ Sword/Civ4BeyondSword.exe

A directory called My Games is can now be found on your drive (in Users/USERNAME/) where you can find a 'Beyond the Sword' folder which should contain your .ini file where you can change the autosave interval (among other things).

Hope this helps, it has been a while since I've installed it myself, but I don't think I've missed any steps. Still, if you run into trouble, just ask and I'll try to help you out.