There are a variety of data visualization tools available, many of them open source, to help you explore existing data visualization or to create your own. Below are a few examples.
Excel is a powerful tool for getting meaning out of vast amounts of data and offers a library of chart and graph types to help users visualize their spreadsheet data.
is a data visualization and analytics platform that enables users to connect to a variety of data sources and explore the data in a simplified way. The drag and drop interface makes it very easy to visualize and create interactive dashboards without any programming skills. (Browse the Tableau to see examples of visuals and dashboards.)
is a web-based data visualization tool for analyzing relationships across time and visualize historical or cultural networks.
is free software for visualizing networks. The main website hosts official tutorials and also links to popular community-developed tutorials.
is a JavaScript library for producing dynamic, interactive data visualizations in web browsers. It is ideal for people who want to develop some JavaScript Programming skills and offers great power and flexibility.