The aim of xloops is to calculate one-particle irreducible Feynman diagrams with one or two closed loops for arbitrary processes in the Standard Model of particles and related theories. Results can be returned both algebraically and numerically. All necessary tensor integrals are treated for arbitrary masses and momenta.

xloops is implemented in C++ based on the GiNaC C++ library for symbolic computation. It currently consists of a library of C++ and GiNaC functions for calculating massive one-loop one-, two-, and three-point, and two-loop two-point integrals to any tensor rank. Future versions of xloops will provide one- and two-loop three- and four-point integrals, as well as an automatic Feynman graph generator.