CityEngine 1.0 is available as a free download on our software library. CityEngine lies within Photo & Graphics Tools, more precisely 3D Design. The CityEngine installer is commonly called CityEngine.exe. The most popular version among CityEngine users is 1.0. This program is an intellectual property of Procedural Inc.
From the developer:
CityEngine is a standalone software that provides professional users in entertainment, architecture, urban planning, GIS and general 3D content production with a unique conceptual design and modeling solution for the efficient creation of 3D cities and buildings.
CityEngine offers unique street grow tools to quickly design and construct urban layouts.
You may want to check out more software, such as ArcGIS for Desktop Updated CityEngine Geoprocessing Tools Patch, which might be similar to CityEngine.