"E-prints are scholarly and professional works electronically produced and shared by researchers with the intent of communicating research findings to colleagues. They may include preprints, reprints, technical reports, conference publications or other means of electronic communication."
E-Print Network - Research Communications for Scientists & Engineers -- "a unique combination of search capabilities to search two distinct areas where scientific and technical information resides electronically, on Web sites and in databases."
arXiv "is an e-print service in the fields of physics, mathematics, non-linear science, computer science, quantitative biology and statistics."