The babelizer is an easy-to-use command line tool that automatically wraps BMI libraries, written in C, C++ or Fortran, so that they can be imported and used as Python packages. Within Python, models, regardless of their core language, appear as classes that expose a BMI. Users are then able to run models interactively through the Python command line, through Python scripts or Jupyter Notebooks, and to use Python-based BMI tools such as the bmi-tester, pymt, or landlab.