RTF is a global modification that replaces all towns in the game.

There are a lot of polygons... you need to run it through Polygon Cruncher or a similar program, although there aren't really any alternatives!
Here's a link to a 7-day trial of version 14 (the archive password is mloads)!
P.S. There's an older version (version 12), but with a "cure" for greed... (the archive password is gN0meS$a), link is active until 03/25/2024.