FRIDA (flexible rapid interactive data analysis) is a generic program for manipulating, fitting, and plotting x,z,y data. It is primarily aimed at spectral analysis, especially in neutron scattering. Note: project has moved away from sf.net.
...It is made for all those who just love gnuplot but who found
that organizing a large number of datasets and plots from the command line is inconvenient.
JGP uses gnuplot as plotting engine.
A wxWidgets-based project aimed to make math-typing, plotting and symbolic math easier; user can easily input, plot and save/load math data in various formats (e.g. MathML). Step-by-step resolution makes this a powerful didactive tool.
JPlot is a multi-purpose data plotting program for use as the graphic front-end of (scientific) software. JPlot is also available as a stand-alone application with a complete and easy-to-use graphic user interface (GUI).