There have been discussions to possibly share our existing work with
Inkscape and FreeCAD to use the same extension format.
Possibly even we could share a web infrastructure, benefiting everyone
and safer maintenance (more people eyes to look at a same code, bigger
community, etc.).

Updating the README to more things which had been discussed or thought
in the past before linking these other FLOSS project to the README and
get them up-to-date with our current work.