MockingHawk

There is an instance reserved for French civil servants but as the product is open source under MIT license, some companies host it for private clients.

We can cite https://mosa.cloud/ for instance

There actually is an open-source form system already: Démarches Simplifiées https://github.com/demarches-simplifiees/demarches-simplifie.... It's maintained by the French government and used by hundreds of administrations. Totally agree that Cerfa would benefit from being open too

Some of the projects are on this org https://github.com/numerique-gouv/ but there are way more projects that the suite numerique there