L7 is a WebGL-powered geospatial visualization engine and browser-based GIS engine designed for high-performance rendering of large-scale 2D and 3D spatial datasets. It functions as a geographic data visualization library that leverages hardware acceleration to display massive datasets and heatmaps within a web browser. The engine features an abstracted basemap integration layer that decouples data visualization from the underlying map provider, allowing for the use of various map providers or offline deployments. It employs a system for visual variable mapping to translate numeric and catego