diff --git a/tools/README b/tools/README
index 853ae50c6..94e69b917 100644
--- a/tools/README
+++ b/tools/README
@@ -1,48 +1,49 @@
 LAMMPS pre- and post-processing tools
 
 This directory contains several stand-alone tools for creating LAMMPS
 input files and massaging LAMMPS output data.  Instructions on how to
 use the tools are discussed in the "Additional Tools" section of the
 LAMMPS documentation.
 
 Tools that are single source files in this directory have additional
 comments that may be useful at the top of the source file.  Tools that
 reside in their own sub-directories have README files you should look
 at.
 
 These are the included tools:
 
 amber2lmp	       python scripts for using AMBER to setup LAMMPS input
 binary2txt	       convert a LAMMPS dump file from binary to ASCII text
 ch2lmp		       convert CHARMM files to LAMMPS input
 chain		       create a data file of bead-spring chains
 colvars		       post-process output of the fix colvars command        
 createatoms	       generate lattices of atoms within a geometry
 data2xmovie	       convert a data file to a snapshot that xmovie can viz
 eam_database	       one tool to generate EAM alloy potential files
 eam_generate	       2nd tool to generate EAM alloy potential files
 eff		       scripts for working with the eFF (electron force field)
 emacs		       add-ons to EMACS editor for editing LAMMPS input scripts
 fep		       scripts for free-energy perturbation with USER-FEP pkg
+i-pi                   Python wrapper for performing path-integral MD (PIMD)
 ipp		       input pre-processor Perl tool for creating input scripts
 lmp2arc		       convert LAMMPS output to Accelrys Insight format
 lmp2cfg		       convert LAMMPS output to CFG files for AtomEye viz
 lmp2traj	       convert LAMMPS output to contour, density profiles
 lmp2vmd                tools for visualizing and analyzing LAMMPS data with VMD
 matlab		       MatLab scripts for post-processing LAMMPS output
 micelle2d	       create a data file of small lipid chains in solvent
 msi2lmp		       use Accelrys Insight code to setup LAMMPS input
 phonon                 post-process output of the fix phonon command
 pymol_asphere	       convert LAMMPS output of ellipsoids to PyMol format
 python		       Python scripts for post-processing LAMMPS output
 reax	       	       Tools for analyzing output of ReaxFF simulations
 vim		       add-ons to VIM editor for editing LAMMPS input scripts
 xmovie		       a quick/simple viz package (2d projections of 3d)
 xmgrace                a collection of scripts to generate xmgrace plots
 
 For tools that are single C, C++, or Fortran files, a Makefile for
 building them is included in this directory.  You may need to edit it
 for the compilers and paths on your system.
 
 For tools in their own sub-directories, see their README file for info
 on how to build and use it.