EpsTk stands for "Encapsulated PostScript Toolkit". The codebase consists of pure M-files (Octave or MATLAB script files), which may be used to create most standard 2D scientific graphics (line charts, bar charts, polar plots, contour plots, etc.). The M-files write EPS files.
The Toolkit was created in 1997 by Stefan Müller of FGAN-FHR (a German research institute) who needed graphical output functions that could run on both Octave and Matlab. He released his kit under the GPL. In 1999, EpsTk became a part of Debian distributions.
EpsTk creates many scientific graphics with plots, bitmaps and text. Also, you can import other graphic sources in form of a bitmap or an EPS-file. The following is the third (of eighteen in version 2.2) demo image.