Gnuplot 4

Gnuplot 4 is a professional and smart command-line driven interactive data and function plotting utility which can be used on UNIX, IBM OS/2, MS Windows, DOS, Macintosh, VMS, Atari and many other platforms.

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 different types of terminals: interactive screen terminals (with mouse and hotkey functionality), pen plotters (like hpgl), printers (including postscript and many color devices), and printings to output file as vectorial pseudo-devices like LaTeX, metafont, pdf, svg, or bitmap png. Gnuplot is easily extensible to include new devices.