Smil is a 2D/3D image library written in C++. It aims to be lightweight, fast, easy to use and to extend. Developed using templates, Smil can be used with any standard types (char, short, int, double, ...). It uses swig and can be wrapped in several languages: for now, python, java, ruby and octave are available. This library was created with the purpose of research on mathematical morphology algorithms and applications.