GnuPlot - Gnuplot is a portable command-line driven interactive data and function plotting utility.

Jupyter - Project Jupyter exists to develop open-source software, open-standards, and services for interactive computing across dozens of programming languages. Ready to get started? Try it in your browser Install the Notebook.

Dr. Geo - Dr. Geo, a software to design & manipulate interactive geometric sketches.

iPython - iPython provides a rich toolkit to help you make the most out of using Python interactively.

Giac/Xcas - Free computer algebra system

Kajero - Interactive JavaScript notebooks - create good-looking, responsive, interactive documents.