IFEFFIT: interactive XAFS analysis and FEFF fitting

IFEFFIT, an interactive program and scriptable library of XAFS algorithms i s presented. The core algorithms of AUTOBK and FEFFIT have been combined wi th general data manipulation and interactive graphics into a single package . IFEFFIT comes with a command-line program that can be run either interact ively or in batch-mode. It also provides a library of functions that can be used easily from C or Fortran, as well as high level scripting languages s uch as Tcl, Perl and Python. Using this library, a Graphical User Interface for rapid 'online' data analysis is demonstrated. IFEFFIT is freely availa ble with an Open Source license. Outside use, development, and contribution s are encouraged.