OpenFisca is a versatile microsimulation free software. This is the source code of the Core module.
The documentation of the project is hosted at http://doc.openfisca.fr/
This is the way to install OpenFisca-Core for development. If you just want to modify the legislation formulas and/or parameters, just follow the installation section of the documentation.
We recommend using Miniconda because it's the simplest solution we've found to install Python scientific packages like NumPy for the different operating systems.
Start by following their quick install page.
git clone https://github.com/openfisca/openfisca-core.git
cd openfisca-core
pip install --editable .
python setup.py compile_catalog