:: installing php5 on linux debian

:: what is php
please take a look this

:: how to install php5 on debian

# aptitude install php5 php5-cli php5-cgi

:: checking php version using cli

# php -v
PHP 5.3.3-7+squeeze1 with Suhosin-Patch (cli) (built: Mar 18 2011 20:10:12)
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies
    with Suhosin v0.9.32.1, Copyright (c) 2007-2010, by SektionEins GmbH

:: links
+ google