Tamaas: a library for elastic-plastic contact of periodic rough surfaces", published in the Journal of Open Source Softwares describes the free and open-source library Tamaas. More than five years in the making, Tamaas is a high performance C++/Python library for the solution of periodic rough contact problems with adhesion, friction and plasticity. It implements state of the art numerical methods to achieve high computational and memory efficiency, while maintaining a user-friendly programming interface that allows rapid deployment of simulations and prototyping thanks to its Python bindings and its interoperability with Numpy.