A standard format for Les Houches Event Files
  A standard file format is proposed to store process and event information, primarily output from parton-level event generators for further use by general-purpose ones. The information content is identical with what was already defined by the Les Houches Accord five years ago, but then in terms of Fortran commonblocks. This information is embedded in a minimal XML-style structure, for clarity and to simplify parsing. 
J. Alwall, A. Ballestrero, P. Bartalini, S. Belov, E. Boos, A.   Buckley, J.M. Butterworth, L. Dudko, S. Frixione, L. Garren...