Processing is a free, open source programming language and development library for the visual arts. It is a software sketchbook, a way to visually learn programming fundamentals, and a tool for creating finished professional work, including mapping networks, textual analysis and producing visualizations. It runs under Windows, OSX and Linux environments, and can export graphics and applets in a variety of formats.

WEAVE (Web-based Analysis and Visualization Environment) is a web-based visualization platform offered by the Institute for Visualization and Perception Research at the University of Massachusetts Lowell. It is designed to visualize any data for any purpose, and to accommodate novice and advanced users alike. It includes the ability to integrate, disseminate and visualize data at nested levels of geography. WEAVE is currently in beta. Both a web-based demo and a download version are available.

Transana is a free, open source program offered by the University of Wisconsin-Madison Center for Education Research for transcribing and analyzing large collections of video and audio data aimed at academic researchers. It enables users to manually transcribe in a variety of levels of detail, identify and access analytically significant sections of their data, manage collections, organize video clips into categories, apply keywords to sections or clips, generate graphical or textual reports, data mine and share markup.

Circos is a free visualization tool for creating publication-quality infographics and illustrations. Its visualizations are arranged in a circle to facilitate exploring relationships between objects and positions, which also has the benefit of offering a high data-to-ink ratio. Though promoted for the sciences, it is highly flexible and can visualize datasets from a wide variety of fields.

TimeRime is a free, web-based timeline application for creating, viewing and comparing interactive timelines. This application requires registration, and timelines created within the application are public.

VisualEyes is web-based authoring tool for creating dynamic visualizations offered by the University of Virginia. It can be used to combine images, maps, charts, video and research data into a single visualization. It is comprehensively documented, including a reference guide to its XML structure and scripting, and to structuring data for inclusion.

Tableau Public is a free data visualization tool aimed at online publishers and academics. It can be used to create an interactive visualization, and also enables users to publish it to the web as an embed or share it via a link. Users must download the desktop interface, and all projects created through the system are saved remotely to the Tableau Public server rather than to the user's local machine. It is availabe for both Windows and OS X, and has a visual interface with a simple drag and drop process.

Kartograph is a pair of free and open source libraries for representing data with a spatial component on webpages or in print. The first library, Kartograph.py, is a Python library that builds lightweight vector graphic maps from either shapefiles or PostGIS tables. These graphics files can be styled either using a cascading style sheet during creation or later on the second library, Kartograph.js. The vector files can also be edited and enhanced in a vector graphics program like Adobe Illustrator.

Kartograph.js allows the user to create interactive maps for web pages and web applications, using vector graphics files and data files to both draw the basemap and the features of interest. Unlike many web-based mapping libraries, Kartograph.js requires no server or even internet connection. All of the pertinent information is in the vector and data files. The results are highly customizable and can absolutely arresting, visually.

Gerbil is a generic framework for visualization and analysis of multispectral and hyperspectral data that strives to both bring new innovations in analysis capabilities and be of use in a wide range of hyperspectral data applications. In a nutshell, Gerbil lets you…

explore a multispectral or hyperspectral image before processing it,

apply common computer vision algorithms adapted to hyperspectral data,

cluster and label image pixels for your application scenario,

assess your own algorithms via high-dimensional data visualization,

use an intuitive interface for teaching multispectral imaging and reflectance analysis.

One example application for Gerbil is finding hidden information in multispectral scans of old manuscripts or art pieces.

CartoDB makes data-driven map visualisation tool. It's very easy to upload a couple of spreadsheets of data, with latitudes and longitudes or addresses, and turn them into clickable markers on maps. There are several types of pre-canned visualisation, such as categories, choropleths or even animated "torque" maps. It's also a sophisticated platform allowing complex visualisations to be built up using Javascript and the CartoDB API.