We present the package SADE (Symmetry Analysis of Differential Equations) for the determination of symmetries and related properties of systems of differential equations. The main methods implemented are: Lie, non classical, Lie-Bäcklund and potential symmetries, invariant solutions, first-integrals, Nöther theorem for both discrete and continuous systems, solution of ordinary differential equations, order and dimension reductions using Lie symmetries, classification of differential equations, Casimir invariants, and the quasi-polynomial formalism for ODE's (previously implemented by the authors in the package QPSI) for the determination of quasipolynomial first-integrals, Lie symmetries and invariant surfaces. Examples of use of the package are given. Nature of the physical problem: Determination of analytical properties of systems of differential equations, including symmetry transformations, analytical solutions and conservation laws.
Method of resolution:The package implements in MAPLE some algorithms (discussed in the text) for the study of systems of differential equations.Restrictions on the complexity of the problem: Depends strongly on the system and on the algorithm required. Typical restrictions are related to the solution of a large over-determined system of linear or non-linear differential equations.Typical running time: Depends strongly on the order, the complexity of the differential system and the object computed. Ranges from seconds to hours.