The longest-running mod series for Civ 4 (more than 5 years of continued development) has finally taken the next logical step in its development, and has been brought to Beyond the Sword expansion. It is also more stable, faster running, more balanced and more packed with goodies than last Warlords version, Total Realism 2.4.
Get the installers here on ModDB: either the full version, or the light version that contains no wonder movies and Great Person popups to consume less bandwidth where that's an issue. The mod also comes with a manual for detailed description of its features; it can be downloaded separately from the files section.