A new high performance parallel implementation of the general Effective Fragment Potential (EFP) method in a form of a portable software library called libefp is presented. The libefp library was designed to provide developers of various quantum chemistry software packages with an easy way to add EFP functionality to the program of their choice. The general overview of the library is presented and various aspects of interfacing the library with third party quantum chemistry packages are considered. The reference implementation of common methods of computational chemistry such as geometry optimization and molecular dynamics on top of libefp is delivered in the form of efpmd program. Results of molecular dynamics simulation of liquid water using the developed software are described. © 2013 Wiley Periodicals, Inc.