The Skyscraper Project
(also SkyscraperSim or Skyscraper Simulator)

Skyscraper is an open-source (C++) realistic building and elevator simulator. Later versions are able to simulate small cities via parallel sim engines.
Custom add-on packages are recommended to fully experience the vast features of this simulator.
For support, visit the Skyscraper Simulator Forum
Release (Version 2.0 Alpha 10, update 6) - 1/30/17:
Windows 64-bit
MacOS
Linux 64-bit
Source Code
Development Version (Alpha 11) - 4/30/18
Windows 64-bit
MacOS (older build)
Linux 64-bit
Source Code
Custom (third party) Add-on Packages
Triton Center floorplans
Build Dependencies (other software)
All Downloads
Skyscraper Simulator Forum
Contact - ryan@thoryk.com