XMGrace, is a 2D plotting program that can be used on
Windows, Linux and OSX.
Tutorial - Line plotting and histograms
Go to the end of the tutorial to the data analysis section
for information on plotting.
Matplotlib is a library of python plotting tools.
Installation directions, user guides and tutorials can all be found here.
Pyplot Tutorials through MolSSI
An assortment of pyplot tutorials made by MOLSSI.