Hi
Someone asked how to get your mod working on the Mac version of Civ4. I am a fan of CivAssist, and a Mac user and programmer, so I took up the challenge.
The problem appears to be that CvPath.py assumes the existence of the Windows Registry and makes Windows-specific Python calls to find the game software and the user's My Documents folder structure.
Soooo, I have worked out a change to CvPath.py that emulates these functions, and Civ4lerts now appears to work on a Mac

.The modified CvPath.py is attached, and subject to confirmation that it still performs on a Windows installation, I recommend that any modders who use CvPath.py should use it in place of the current one wherever it's needed. Then your mods are more likely to be compatible with the Mac version.
[Techie details alert]
My change checks sys.platform to determine whether to use my Mac OS X code or your original code, and the latter is unchanged except that I've put import _winreg within the conditional code section used for Windows only, so it doesn't fail on a non-Windows system.