In this paper is reported the software development for power systems analysis using several techniques combining the object oriented programming paradigm, computer graphics techniques, distributed data base and software engineering. Three software packages have been implemented: CAPS, SIGVNS and TREINOM. CAPS package is oriented for interactive analysis of power systems and electric markets. SIGVNS is intended for calculation of the new replacement value in electric distribution systems. TREINOM configures a 3D virtual reality environment for simulation of basic operation and maintenance tasks of high voltage power transformers. All packages have been implemented on Windows XP using Borland C++ platform, Java, 3D Studio Max, VRML, Java 3D, CORBA and database SQL. Applications include real systems of ELETRONORTE and CEMAR, two Brazilian utilities of transmission and distribution, respectively.