DANTON: a Monte-Carlo sampler of $\tau$ from ${\nu }_{\tau }$ interacting with the Earth

A preliminary version (v0.2.1) of the DANTON Monte-Carlo package is presented. DANTON allows the exclusive sampling of (decaying) $\tau$ generated by ${\nu }_{\tau }$ interactions with the Earth. The particles interactions with matter are simulated in detail, including transverse scattering. Detailed topography data of the Earth can be used as well. Yet, high Monte-Carlo efficiency is achieved by using a Backward Monte-Carlo technique. Some validation results are provided.