Problem: We are currently using Ploticus, a software that has not been updated since 2014. Last time Debian was upgraded Ploticus had to be ported and that will only continue being the case, if no change is made.

Solution: Move over to DataDraw (http://datadraw.org/). Since ploticus was last updated in 2014, the author has moved over to DataDraw, a python server side software, available on pip, that makes SVGs. That could then be fed to Thumbor to provide an PNG. DataDraw has similar syntax to ploticus, so probably users will notice little difference between the two. DataDraw is under an MIT licence, free enough for WMFs standards.

From ploticus news page:

16 Mar 2023 .... Announcing DataDraw

A new all-python function library that produces SVG, and inherits many of the working notions used in ploticus. Ongoing development will be centered there. The earlier SVGdatashapes python effort mentioned here is now deprecated.

17 Dec 2016 .... Announcement ....
Ongoing ploticus development / support is halted.
Thanks to all who've been involved since the late 1990's. It's been a lot of fun! -Steve