Hi, I have been working on an extension to GiNaC for differential geometry, and I have released a first version, available from <https://sourceforge.net/projects/libwedge/>. Current features include: - Vector spaces: determine a basis from a list of generators, and similar computations. - Manifolds and differential forms: exterior derivative; wedge product. - Lie groups: the general linear group; subgroups determined by the choice of a subalgebra; abstract Lie groups defined in abbreviated form, e.g. writing (0,0,12) for the Heisenberg group, characterized by the existence of a basis of left-invariant one-forms e1,e2,e3 such that de3=e1 ^ e2 and e1,e2 are closed. - Riemannian metrics and G-structures, defined on a Lie group or a coordinate patch of a generic manifold, and represented by an orthonormal basis of 1-forms (adapted frame); spinors, Clifford multiplication. - Connections: the Levi-Civita connection; curvature; covariant derivatives; define connections on generic manifolds and impose conditions on the Christoffel symbols, e.g. to obtain curvature conditions. I thought maybe someone in this list would be interested. Diego Conti