PHP

What is PHP?
PHP (recursive acronym for PHP: Hypertext Preprocessor) is a widely-used open source general-purpose scripting language that is especially suited for web development. The PHP code can be embedded into HTML or it can embed HTML.

What distinguishes PHP from something like client-side JavaScript is that the code is executed by the web server, generating a web page which is then sent to the client. The client would receive the results of running that script, but would not know what the underlying code was.

The best things in using PHP are that it is extremely simple for a newcomer, but offers many advanced features for a professional programmer.

The PHP interpreter
The PHP interpreter is executed whenever the Apache web server application sees PHP code. The location of the PHP interpreter, if using the XAMPP stack, is xampp\php\php.exe. If you wish to set this executable as a PATH variable using Windows, see the PATH_Variable article. By doing so, you can run the PHP interpreter yourselv at the command prompt in Windows.

php -i
php -i is a command run from the Windows command prompt (read  Command Prompt for more info), which displays PHP information. The configuration of Xdebug for Eclipse PDT is one example in which running the php -i command is used.

The following command prompt screen output shows how one would redirect the output of the php -i command to a text file. You can then browse to the text file location, open it, and copy the entire output for the purpose of pasting it into the Xdebug.org Installation Instructions text form.

C:\Documents and Settings\CISLab6>php -i > C:\phpoutput.txt

php -m
php -m outputs the built in (and loaded) PHP and Zend modules. Run this command to see if Xdebug installation is successful. An example of its use is as follows (notice that "Xdebug" is listed as a Zend module):

C:\Documents and Settings\CISLab6>php -m [PHP Modules] bcmath bz2 calendar com_dotnet Core ... [Zend Modules] Xdebug

php -h
php -h outputs a list of command line options with one line descriptions of what they do.

php.ini
In order to successfully compile and show the Xdebug module after running the php -m command, you need to edit php.ini found within the xampp\php directory. At approximately line 1975 of code, the Xdebug module directives are listed. The Xdebug tailored instructions told me to add zend_extension = E:\xampp\php\ext\php_xdebug-2.1.1-5.3-vc6.dll to php.ini, which I did when I uncommented and replaced ;zend_extension = "E:\xampp\php\ext\php_xdebug.dll" with zend_extension = E:\xampp\php\ext\php_xdebug-2.1.1-5.3-vc6.dll