Multi-body simulation is a key method for design, homologation and research of railed vehicles of all kind. Not only the “classic” assessment of the rail-to-wheel forces and running stability but also many other common and advanced tasks can today be handled by multi-body simulation. This paper gives an overview of the multi-body simulation state of the art for the different fields of application, lifecycle steps and user groups in the railway industry, along with some examples of basic and advanced applications and current research topics.