GnuPlot is described as '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' and is a popular graphing calculator in the education & reference category. There are more than 50 alternatives to GnuPlot for a variety of platforms, including Windows, Mac, Linux, Web-based and Android apps. The best GnuPlot alternative is MATLAB. It's not free, so if you're looking for a free alternative, you could try GNU Octave or Matplotlib. Other great apps like GnuPlot are GeoGebra, LabPlot, OriginPro and Desmos.
It is open source and plots can be included in the python programs unlike in GNUPlot