I think jqPlot should be replaced with another library that is actively developed and supports retina displays.
The problems with retina display are known to jqPlot since 1,5 years and there was no further development to jqPlot since more than a year. So remaining at jqPlot will make piwik worser every day.
Could you also nominate any choice?
I've just shortly found this comparison but I'm not very well awarded about plotting and I can't really say.
One important aspect of a new graphing library is be to generate graphs that are accessible see #4167
Here is a good looking Graphs library released by Mozilla: https://github.com/mozilla/metrics-graphics
MetricsGraphics.js on example page was suspend my browser. We need some tests with many graphs on one page.
Like to see if there is a good graphs library selected for.