Contains tools for open assessment and modelling in Opasnet, a wiki-based web site and workspace for societal decision making (see < http://en.opasnet.org/w/Main_Page> for more information). The core principle of the workspace is maximal openness and modularity. Variables are defined on public wiki pages using wiki inputs/tables, databases and R code. This package provides the functionality to download and use these variables. It also contains health impact assessment tools such as spatial methods for exposure modelling.