CodeCity is written by Richard Wettel and is an integrated environment for software analysis, in which software systems are visualized as interactive, navigable 3D cities.

The classes are represented as buildings in the city, while the packages are depicted as the districts in which the buildings reside. The visible properties of the city artifacts depict a set of chosen software metrics, as in the polymetric views of CodeCrawler.

Here is an example of a city generated for the ArgoUML Java system:

For more details you can check the official website.

Publications

1. Richard Wettel and Michele Lanza. Program Comprehension through Software Habitability. In Proceedings of ICPC 2007 (15th International Conference on Program Comprehension), p. 231—240, IEEE CS Press, 2007. →
2. Richard Wettel and Michele Lanza. Visualizing Software Systems as Cities. In Proceedings of VISSOFT 2007 (4th IEEE International Workshop on Visualizing Software For Understanding and Analysis), p. 92—99, 2007. DOI URL →

License: (not specified, but based on Jun which makes it GPL as well)