The purpose of QtiPlot was to develop a free, platform independent clone of
Origin. The result is still far away from its model, but there's a "wish to"
list that is being constantly worked on.

Features:

  * Neat 2D and 3D data plotting
  * ASCII-Import
  * Spreadsheet and calculations in column-logic
  * Great non-linear y=f(x) curve fitting and estimation of statistical
    errors of the fit-parameters

WWW: http://soft.proindependent.com/qtiplot.html