JavaScript is one of the most popular programming languages on the web. Despite the language popularity and the increasing size of JavaScript systems, there is currently no visualization tools that can be used by developers to comprehend, maintain, and evolve JavaScript software. In this paper, we introduce JSCity, an implementation in JavaScript of the well-known CodeCity software visualization metaphor. JSCity relies on JavaScript features and libraries to show “software cities” in standard web browsers, without requiring complex installation procedures. We also report our experience on producing visualizations for 40 popular JavaScript systems using JScity.