Manifesto & history

The development of OpenFisca began in May 2011 at the CAS (renamed France Stratégie / Commissariat général à la stratégie et à la prospective in April 2013) with the support of the IDEP.

OpenFisca was originally developed as a desktop application using the Qt library with a Python API. This original source code was released under a free software license in November 2011.

In the early 2014, Etalab started using OpenFisca and soon became a major contributor. It then decided to:

  • separate the computing engine from its desktop user interface;
  • offer a web API in addition to the Python API;
  • demonstrate the value of the web API by developing sample applications including a web interface to simulate personal cases;
  • offer a public access to this web API;
  • stop the development of the Qt version.

The core was improved extensively by Etalab, while the French model was being improved and updated by the CGSP with the help of the IDEP and the IPP, soon to be joined by the French State Startups incubator which used and extended the model for digital public services purposes.

The 2016 OGP Paris summit saw a demonstration that a small team could model the base of a tax and benefit system from scratch under 36 hours, when the Sénégal income revenue tax was modelled and made usable with a web UI during the OGP hackathon, winning the team the first prize.

This led in 2017 to a joint effort from Etalab and beta.gouv.fr with a major focus on stability, ease of contribution and reusability. This lead to the full rewrite of the documentation, the opening of openfisca.org to replace openfisca.fr, and the addition of new contributors from other French agencies, as well as international reusers with Barcelona joining Tunisia.