These free and open source data visualization tools generally utilize JavaScript, but also web standard technologies such as HTML 5 and CSS. Some have free versions, but charge a fee for commercial use.
amCharts is a library of JavaScript charts which include column, bar, line, area, step, smoothed, candlestick, OHLC, pie, donut, radar, polar, XY, scaller, bubble, bullet, gauges, funnel and pyramid charts. Stock charts are available as a separate product for financial time series data. amMap is an interactive JavaScript/HTML5 maps library. Pricing is based on the number of web sites that will use the libraries.
Bonsai is a free, lightweight JavaScript graphics library with a simple API and SVG renderer. Supports a variety of graph types with keyframe and time based animations.
CanvasXpress is a standalone HTML5 graphing library written in JavaScript and distinguishes itself by its ability to handle complex data. It supports a large number of visualisations for scientific and non-scientific data, with support for data sorting, grouping, transposition and clustering. It is free for non-commercial use.
CanvasJS is an HTML5 and JavaScript charting library built on the Canvas element. This means graphs render across most platforms and devices, and rich dashboards can be created. The resulting graphics are fast with good interactive functionality such as zooming and panning. Free for non-commercial use, and modest fees otherwise.
Chart.js is a free library of 6 chart types (line, bar, radar, pie, polar and doughnut). It uses the HTML5 canvas element and is extremely lightweight.
D3.js is a free JavaScript library for creating and manipulating data based documents and is rapidly becoming something of a de facto standard. It utilises web standards such as HTML, SVG and CSS to exploit the web browser environments. This is an environment for developers with similarities to jQuery but supports styles, attributes and other properties as functions of data.
Dojo charting is a easy to use free package that allows charts to be created in HTML or JavaScript. Charts can be rendered in SVG, VML, Sliverlight and Canvas.
elycharts is a free, pure JavaScript charting library with support for a number of useful features. These include legend and label support, mouse tracking, tooltips, templates and animations. Supports most common chart types and if free for commercial use.
Flotr2 is a free graphing library for Canvas written in JavaScript. It supports line, bar, candle, pie and bubble charts.
FusionCharts – probably the largest collection of JavaScript charting types available, with over 90 chart types – from the simple to the complex (funnel, pyramid, zoom line etc). Charts work on all popular desktop and mobile devices. Licensing is based on one-time purchase.
gRaphael is a free JavaScript graphics library based on the Raphael graphics library. It supports most popular graphing methods (lines, bars, pie etc.).
Highcharts JS from Highsoft is a JavaScript charting library supporting a wide variety of charting types, including line, spline, area, area-spline, column, bar, pie, scatter, angular gauges, area-range, area-spline-range, column-range, bubble, box plot, error bars, funnel, waterfall and polar chart types. It is free for non-commercial use and moderately priced for commercial use.
The free JavaScript InfoVis Toolkit provides a wide range of chart types and layouts for interactive web visualisations. These include area, pie and bar charts, sunburst, icicle, treemap, forceDirected, spaceTree, RGraph, HyperTree and other advanced visualisations.
jqPlot is a charting plugin for the jQuery JavaScript framework. This is an open source project and provides great flexibility in the construction of line, bar and pie charts. There are numerous style options, date axis upport, rotated axis text, automatic trend line computation, tooltips and data point highlighting.
JS Charts is a JavaScript based chart generator with support for XML, JSON and JavaScript Array data sources. A free version is available but charts are watermarked. The paid versions come in commercial and non-commercial versions.
PlotKit is a Chart and Graph Plotting Library for Javascript. It has support for HTML Canvas and also SVG via Adobe SVG Viewer and native browser support.
Rickshaw is a JavaScript toolkit for creating interactive time series graphs and is built on d3.js, meaning they are drawn with standard SVG and styles with CSS. It is a free, open source product.
RGraph is a canvas and JavaScript based charts library built for web charts and supports over twenty different types of visualisation. Using the <canvas> tag, RGraph creates these charts inside the web browser using JavaScript, meaning quicker pages and less web server load. This leads to smaller page sizes, lower costs and faster websites.
ShieldUI JavaScript framework offers JavaScript HTML5 components for streamlined development, supporting over 40 different component types and spans over multiple development platforms . The Free-For-Non-Commercial version of the JavaScript Framework ShieldUI can be utilized in non profit projects.
TufteGraph is as free JavaScript charting library using jQuery. Much of the layout is implemented through CSS and configuration is via dynamic functions – making for a compact API. Limited testing of browsers however.
ZingChart is a javaScript charting library that supports literally hundreds of chart types (there are 38 types of bar chart alone). These include bar, scatter, radar, piano, gauge, sparkline, line, bubble, bullet, stock, maps, pie, area, funnel, Venn, Stacked, treemap … and so on. Canvas and SVG rendering is supported for HTML5 support, and JSON is used for data interchange. Pricing is based on usage (i.e. separate licenses for internal use of web publishing).