TTSIM provides the computing engine powering the German Taxes and Transfers Simulator GETTSIM.
The documentation is available at https://gettsim.readthedocs.io. If you want to use it or help out in its development, feel free to get in touch! The ideal ways are to open an issue if you find a bug or something does not work as expected, or by joining our Zulip Chat at https://gettsim.zulipchat.com.