mdf stands for man systematic strategies data-flow. mdf is a toolkit for expressing programs in Python as directed acyclic graphs (DAGS). mdf was developed to make it easier to wire together quantitative trading strategies composed of related computations over time-series data, but it can be used as a toolkit for describing general computations as DAGS.
The full documentation, with examples, can be found here: http://mdf-data-flow-programming-toolkit.readthedocs.org/en/latest/