Scilab is an open-source math package similar to Matlab. I use it to make plots for my physics labs.
I'll add any little scripts I write that help with my workflow.
Update: The IPython Notebook is an alternative to using Scilab. The workflow is simpler, you learn python while using it, and the community is more alive. I still think making plots should be easier than this.
Takes data in the form of a CSV and plots it.
