  Betweeness centrality is one of the most important concepts in graph
analysis. It was recently extended to link streams, a graph generalization
where links arrive over time. However, its computation raises non-trivial
issues, due in particular to the fact that time is considered as continuous. We
provide here the first algorithms to compute this generalized betweenness
centrality, as well as several companion algorithms that have their own
interest. They work in polynomial time and space, we illustrate them on typical
examples, and we provide an implementation.
