@J F Ogilvie I do not have the same opinion. It is correct that Maple and the Physics Package is excellent for GR, but it is just incorrect to suggest that it is restricted to this field. As a professional physicist and researcher, I use it on a daily basis. It is a very powerful tool that can address many areas of Quantum Mechanics. Its capabilities spans from functional derivative to some very complex non-commutative algebraic operations, to mention only a few of its possibilities. Furthermore, it should be considered as a whole. Even if one is not directly involved in GR for instance, because of GR, the tensor engine of Maple is very powerful and simple to use, and an incredible number of fields requires tensor calculus.