Who is using it?

IDF Component Manager:

https://docs.espressif.com/projects/idf-component-manager/en/latest/index.html

Trossen Robotics:

https://docs.trossenrobotics.com/interbotix_xslocobots_docs/ros_interface/ros1/software_setup.html

pymadcap:

https://pymadcad.readthedocs.io/en/latest/reference/mesh/web.html

ScyllaDB:

https://sphinx-theme.scylladb.com/stable/examples/collapse.html