Name                    Last modified       Size  Description

 Parent Directory        13-Jan-2021 01:30      -  
 Changes                 15-May-2010 07:29     1k  
 Makefile                15-May-2010 07:32     2k  
 xcomment-doc.pdf        15-May-2010 07:32    82k  
 xcomment-doc.tex        15-May-2010 07:32    21k  
 xcomment.sty            15-May-2010 07:31     1k  
 xcomment.tex            15-May-2010 07:32     5k  

Save the files xcomment.sty|tex in a directory, which is part of your 
local TeX tree. 
Then do not forget to run texhash to update this tree.
For more information  see the documentation of your LATEX distribution 
on installing packages into your LATEX distribution or the 
TeX Frequently Asked Questions:
(http://www.tex.ac.uk/cgi-bin/texfaq2html?label=instpackages).