Warning: this only works on Intel Macs, not PowerPC!
The program wine runs Windows software on non-Windows systems

There are numerous ways of installing wine on Mac OS X. I'll be using PlayOnMac, since it's user-friendly.
Install PlayOnMac
Download PlayOnMac:
Once downloaded, open the PlayOnMac DMG file, and drag the PlayOnMac icon into the Applications folder:
PlayOnMac is installed. Now it needs to be configured.
Open your Applications folder in Finder, and run PlayOnMac.
Download & install XQuartz when prompted:
Just keep pressing "Continue" until it installs:
Now reboot normally to finish the installation of XQuartz:
If a program called xterm starts when you're system reboots, just close it.
After rebooting, start PlayOnMac again. This time it will prompt you to install Microsoft fonts.
All done. PlayOnMac is now installed & configured!
Install BotF
If you haven't done so already, you'll need to download the main BotF multi-installer from the downloads section of this site!
Once that's done, click "Install" in PlayOnMac. You'll see a lot of apps listed, but BotF is not one of them. Don't worry, just click "Install a non-listed program".
Each app in PlayOnMac is installed in it's own sandbox (so install it in a new virtual drive):
Give it a name with no spaces (I called it BOTF):
Make sure you configure wine, and install some libraries:



When prompted to install libraries, choose to install DirectPlay, as this is needed to join multiplayer games.
Now locate the BotF installer:
And install it normally:
Ensure you make a shortcut to Trek.exe or it won't be listed!
Give it a name:
And now it should be installed and listed:
Try it out!
Just hit "Run". If the screen is black, just click the mouse. This happens because the intro video doesn't play.
Don't worry if you get this error after quitting, it's nothing important

Tip: Installing Mods
If you're installing mods, make sure you install them to the existing BotF installation:
Let me know if it works for you!