X-ray absorption spectroscopy (XAS) is a powerful tool to study local electronic and atomic structure of solids, liquids and gases in a wide range of external conditions determined by temperature, pressure, etc. The structural information can be extracted from the extended x-ray absorption fine structure (EXAFS) having the oscillating character and located beyond the absorption edge of an atom. General approach to the analysis of EXAFS spectra requires an intensive use of modern computers to carry out interactive data analysis and to perform intensive numerical simulations and graphical representation of results.

This report will present the EXAFS data analysis software package, called EDA, which was developed by the author starting from 1988 for use on IBM PC compatible computers. The package allows an extraction of EXAFS signals and their modeling by semi-empirical (model-dependent) and ab initio (model-independent) approaches. During last decade the EDA package has been tested on a number of applications and showed good results and flexibility in the analysis of experimental data.

The possibilities of the EDA package will be demonstrated for several practical cases as phase transition from local point of view (dehydration of molybdenum trioxide-hydrates and decomposition of perovskite-type rhenium trioxide), local structure of transition metal ions in nanocrystalline oxide compounds and of rare-earth ions in xerogels.