XLOOPS — a package calculating one- and two-loop diagrams

A program package for calculating massive one- and two-loop diagrams is introduced. It consists of five parts: • aphical user interface, ines for generating diagrams from particle input, edures for calculating one-loop integrals both analytically and numerically, ines for massive two-loop integrals, rams for numerical integration of two-loop diagrams. he graphical user interface and the text interface to Maple are presented.