Blesta currently uses jqplot, and should maintain (inclusion of) that until at least 5.0 for backwards compatibility, however, all existing graphs (that we control) should be updated to use the new library: nvd3

This includes:

• System Overview widget
• Billing Overview widget
• System Status widget

An example area graph is in the office share, Blesta Dev > nvd3 > examples > stackedAreaChart-TEST.html

For the system status widget see the donutChart.html example in the same directory. The example on the right, containing half a donut could be a good replacement. The text in the middle could represent the health %. The profile on this chart is fairly high though, and a bulletChart (bulletChart.html) may be more appropriate depending on how flexible it is.

Look at implementing a direct D3 (not using nvd3) fill gauge from http://bl.ocks.org/brattonc/5e5ce9beee483220e2f6

I suggest using something similar to the pink gauge on the left (but obviously a different color) and making it square instead of round. I was able to accomplish this by editing the markup.

OR this super simple gauge that similar to what we have now: http://bl.ocks.org/ameyms/9184728

Known issues:

• There appears to be an nvd3 bug preventing stacked graphs from starting their Y axis at 0, which is useful for displaying only unsigned values:
  https://github.com/novus/nvd3/issues/602
  A graph with only 0 values (such as on the System Overview) will show a Y-Axis range of [-1, 0, 1] rather than [0, 1].

• Toggling a graph line off can cause a JS error and keep showing the graph line. You will need to have the graph regenerated before it will fix itself (e.g. resizing the page or re-toggling the option) (Fixed with v1.8.2)
  https://github.com/novus/nvd3/issues/1093