This package implements the Smoothed Dissipative Particle Dynamics (SDPD) method for modelling fluids at mesoscale and diffusion of colloids. Currently it adds pair style sdpd/taitwater/isothermal for modelling water at isothermal conditions using the Tait equation of state. It also adds fix meso/move command to move mesoscopic SPH/SDPD particles with prescribed velocity and fix rigid/meso command to integrate rigid bodies composed of mesoscopic SPH/SDPD particles. Creator of this package is: Morteza Jalalvand Institute for Advanced Studies in Basic Sciences jalalvand.m AT gmail DOT com