gnuplot by Ciro Santilli 32 Updated Created
Tends to be Ciro Santilli's first attempt for quick and dirty graphing: github.com/cirosantilli/gnuplot-cheat.
domain-specific language. When it get the jobs done, it is in 3 lines and it feels great.
When it doesn't, you Google for an hours, and then you give up in frustration, and fall back to Matplotlib.