Free data and information visualization software

high-performance dynamic programming language

Matplotlib (portmanteau of MATLAB, plot, and library) is a plotting library for the Python programming language and its numerical mathematics extension NumPy. It provides an object-oriented API for embedding plots into applications using general-purpose GUI toolkits like Tkinter, wxPython, Qt, or GTK. There is also a procedural "pylab" interface based on a state machine (like OpenGL), designed to closely resemble that of MATLAB, though its use is discouraged. SciPy makes use of Matplotlib.

The Visualization Toolkit (VTK) is a free software system for 3D computer graphics, image processing and scientific visualization.

thumb|300px|right|Example of Gephi network visualizationGephi ( ) is an open-source network analysis and visualization software package written in Java on the NetBeans platform.

ggplot2 is an open-source data visualization package for the statistical programming language R. Created by Hadley Wickham in 2005, ggplot2 is an implementation of Leland Wilkinson's Grammar of Graphics—a general scheme for data visualization which breaks up graphs into semantic components such as scales and layers. ggplot2 can serve as a replacement for the base graphics in R and contains a number of defaults for web and print display of common scales. Since 2005, ggplot2 has grown in use to become one of the most popular R packages.

ParaView is an open-source multiple-platform application for interactive, scientific visualization. It has a client–server architecture to facilitate remote visualization of datasets, and generates level of detail (LOD) models to maintain interactive frame rates for large datasets. It is an application built on top of the Visualization Toolkit (VTK) libraries. ParaView is an application designed for data parallelism on shared-memory or distributed-memory multicomputers and clusters. It can also be run as a single-computer application.

MayaVi is a scientific data visualizer written in Python, which uses VTK and provides a GUI via Tkinter. MayaVi was developed by Prabhu Ramachandran, is free and distributed under the BSD License. It is cross-platform and runs on any platform where both Python and VTK are available (almost any Unix, Mac OS X, or Windows). MayaVi is pronounced as a single name, "Ma-ya-vee", meaning "magical" in Sanskrit. The code of MayaVi has nothing in common with that of Autodesk Maya or the Vi text editor.