Flot

Flot is a JavaScript plotting library for jQuery that enables the creation of interactive charts on web pages. It renders plots in a canvas, allowing multiple data series to be displayed with relatively small code. Flot focuses on a lightweight, easy-to-use approach for common chart types such as lines, bars, and points, with support for stacked series, grid lines, legends, and customizable axes. The library’s functionality is extended through a large ecosystem of plugins that add features like tooltips, hover interactions, panning and zooming, and specialized charts such as pie charts.

The core API is designed for straightforward integration. After including jQuery and the Flot script, a plot is created by calling a function like $.plot(target, data, options). Data is supplied as an array of series, each with a data array and optional styling such as color, label, and line or bar configuration. The x-axis can be configured for numeric scales, time-based scales (with mode: "time"), or category-based axes. Axes, grid appearance, legends, and series presentation are all adjustable via the options object.

Data can be provided as simple x-y pairs or as more complex series objects, and plugins extend the core capabilities with additional rendering and interaction options. Flot is open-source and widely used in web projects as a lightweight alternative to larger plotting libraries, particularly when jQuery is already in use. Its modular, plugin-based design has contributed to a robust ecosystem, though performance may vary with very large datasets.