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Gnuplot is a portable command-line driven interactive data and function plotting utility. It was originally intended as to allow scientists and students to visualize mathematical functions and data. It does this job pretty well, but has grown to support many non-interactive uses, including web scripting and integration as a plotting engine for third-party applications like Octave. Gnuplot supports many types of plots in either 2D and 3D. It can draw using lines, points, boxes, contours, vector fields, surfaces, and various associated text. It also supports various specialized plot types. »

QtiPlot is a professional scientific data analysis and visualisation solution. It is meant to be a cheap alternative to proprietary and costly software such as Origin, SigmaPlot, Regressi or Igor Pro.

Plot graphs in real-time while the CSV data is still being generated by your application. Very easy GUI to manage 1000s of data series efficiently. Includes data logging API. Java, open-source, free. Well documented.

SigmaPlot is a scientific data analysis and graphing software package with an intuitive interface for all your statistical analysis and graphing needs that takes you beyond simple spreadsheets and helps you to produce high-quality graphs without spending hours in front of a computer.

Technical graphing and data analysis for Macintosh and Windows. IGOR Pro creates publication quality scientific graphics used by scientists and engineers around the world. IGOR Pro 6 is an extraordinarily powerful and extensible scientific graphing, data analysis, image processing and programming software tool for scientists and engineers.