For the installation process please go to the ISSM website 
http://issm.jpl.nasa.gov/ which is often updated

LINUX:
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http://issm.jpl.nasa.gov/doc_html/installation_linux64.html

MAC:
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http://issm.jpl.nasa.gov/doc_html/installation_macosx32.html

WINDOWS:
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http://issm.jpl.nasa.gov/doc_html/installation_winxp32.html

