The itx file is the input used by Itranslator to create the Devanagari and Transliteration versions of Guru Gitam. You need to install two fonts (URW Palladio & sanskrit-99) to view or print these files. You can download the fonts or install Itranslator which will install the fonts for you.
if you want to save the mp3 above and your browser automatically plays it, in IE explorer you can
'right-click' the link and choose <save link as>