Peity is a jQuery plugin for creating word-sized charts (sparklines) using HTML5 <canvas>.

It has support for bar, line and pie charts where color, width, radius and delimeter can be updated.

The plugin adds a "change" event trigger to the graph elements, so, once their data is updated, the charts can be regenerated instantly.

If you would like to add new chart types, Peity can be extended by adding the new charting functions easily.

D3 is a lightweight and free JavaScript library for manipulating HTML documents based on data.

It can help us visualizing the data as HTML or SVG quickly, handle interactivity, and incorporate smooth transitions + staged animations into web pages.

The library can be used as a visualization framework (like Protovis) or as a framework to build pages (like jQuery).

D3 is not the traditional visualization framework that comes with it limits and ready-to-use templates. Rather, it solves only the crux of the problem: efficient manipulation of documents based on data which ends up in a serious flexibility.

AwesomeChartJS is an open source JavaScript library for creating charts using the HTML5 <canvas> tag.

The library is standalone (doesn't require any JS frameworks) and works very straightforward with an easy-to-use function.

It supports multiple chart types:

• vertical and horizontal bar charts
• pareto bar charts
• pie charts (whole or part)
• exploded pie charts
• ring/doughnut charts

It focuses on simplicity and doesn't offer too much for customization other than the title, chart type and labels. Yet, simplicity is sometimes all we ask for.

Arbor.js is a graph visualization library built with web workers and jQuery.

It provides an efficient, force-directed layout algorithm, abstractions for graph organization and screen refresh handling.

The library doesn't force a specific method for screen-drawing and you can use it with canvas, SVG, or even positioned HTML elements; the best one that fits your project.

Arbor.js simply helps you focus on the graph data and its style rather than spending time on the physics math that makes the layouts possible.

It also comes with a well-documented API and creative demos.

SVGGraph is an object-oriented PHP library for creating simple and interactive charts with SVG.

There are multiple chart types supported like (3D) bar, line, (3D) pie and scatter where every chart has its own PHP class in a seperate file. So, you can use only the features you need.

Charts can be customized in many ways including the title, description, paddings, colors, labels and much more.

Every new release has only support for PHP5 but a pretty old, PHP4 compatible version is still offered.

canvasXpress is a free JavaScript graphing library based on the <canvas> tag of HTML5.

It supports multiple graph types including bar, line, dotplots, area, stacked, heatmaps, pie charts and more.

The outputs are interactive as hovering over the items can display values.

And, it is possible to customize every aspect of them including colors, text, hiding/showing elements, etc.

canvasXpress works in all major browsers including IE6.

DDChart is a jQuery plugin for creating bar charts where it is possible to digg the data deeper and deeper.

It works by clicking a bar inside the chart and it can instantly display a new chart which focuses on that item.

Charts are interactive, they respond to mouseovers with tooltips that include the data and they have a nice animation on load.

DDChart requires the data to be in JSON format and it is jQuery UI compatible (which is great for easy styling).

HumbleFinance is an HTML5 data visualization tool that looks and functions similar to the Flash chart in Google Finance.

It makes use of the Prototype and Flotr libraries and is not limited to displaying financial data but any two 2d data sets which share an axis.

The data needs to be stored in JavaScript variables and requires 3 parameters to be set before running the function to create the chart.

It is possible to manually select a part of the data (with a slider-like interface) and zoom to that part. This is a very useful function when working with large datasets,

JpGraph is a feature-rich PHP library for creating good looking charts.

It has support for almost any chart type including bar, line, pie, scatter, radar, field, stock and much more.

Some of the charts have the option to be created in 3D and they are all web-friendly (usually 2-3 kb).

The library is very flexible, any number of plots can be drawn in every chart, objects can be rotated, etc.

JpGraph has built-in images for plot marks including 3D rendered markers like diamonds, squares, bevels, balls and pins.

And, a very original feature, it has a pre-defined function to create flags for 200+ countries.

To sum up, the library is really an impressive one and it is free to be used in non-commercial, open-source or educational projects.

RGraph is a free graph library that uses the HTML5 canvas tag.

Using the library, it is possible to create a wide variety of graph types:

• bar, pie, donut, gantt, radar, funnel, bi-polar charts
• line and scatter graphs
• LED display
• meter
• odometer
• progress bar

The charts are interactive (respond to mouse-overs and clicks) and, optionally, they can load with animations or zoom to a specific point.

There is also an annotation feature where you can draw over the graphs for highlighting them.

P.S. RGraph is only free for personal use.