  The modelling and analysis of biological systems has deep roots in
Mathematics, specifically in the field of Ordinary Differential Equations.
Alternative approaches based on formal calculi, often derived from process
algebras or term rewriting systems, provide a quite complementary way to
analyse the behaviour of biological systems. These calculi allow to cope in a
natural way with notions like compartments and membranes, which are not easy
(sometimes impossible) to handle with purely numerical approaches, and are
often based on stochastic simulation methods. The Calculus of Wrapped
Compartments is a framework based on stochastic multiset rewriting in a
compartmentalised setting used for the description of biological and ecological
systems. We provide an extended presentation of the Calculus of Wrapped
Compartments, sketch a few modelling guidelines to encode biological and
ecological interactions, show how spatial properties can be handled within the
framework and define a hybrid simulation algorithm. Several applications in
Biology and Ecology are proposed as modelling case studies.
