City Generator is a free and open-source procedural generation tool for creating American-style grid based cities. The source code is available on GitHub under the GPL 3 license, composed almost entirely of TypeScript code.
Features of City Generator include:
.png download
.png heightmap download
.svg download
.stl download
Several colour themes including Google Maps, Apple Maps, and hand-drawn styles
Pseudo-3D buildings
Open source
City Generator can export STL files that can then be imported into a 3D tool of choice for creating 3D levels. We should this process in Blender as well as the process of generating a city in City Generator in the video below.