The Mesoscopic simulation models and High-Performance Computing ESDW (Extended Software Development Workshop) is organised by CECAM-FI (Aalto University, Finland) in collaboration with the CSC IT Center for Science and will mix three different ingredients: (1) workshop on state-of-the-art challenges in computational science and software, (2) CSC -run school, and (3) coding sessions with the aid of CSC facilities and expertise. The plan is to involve and contact a number of groups in Europe interested in topics where the usage of this methodology is essential and/or current code development / usage is actively going on.