We recommend the use of the Apache HTTP Server, a free, open-source server which has been the most popular web server on the Internet since April of 1999. The February 2005 Netcraft Web Server Survey found that more than 68% of the web sites on the Internet are using Apache, thus making it more widely used than all other web servers combined.

We recommend the use of PHP as the programming language for this project. PHP is a widely-used general-purpose scripting language that was specifically written for web page creation. PHP is free, easy to learn, and has many extensions available. PHP 5 offers object-oriented capabilities and an XSL transformation extension. PHP code is faster than other languages to code and to execute, and can run unaltered on different web servers and operating systems.

Although Java is another language that could potentially be used, it is more difficult to learn, may take longer to develop an application in, and Java developers typically cost more than PHP developers. There is also a lack of Java developers at UC Berkeley, which would make it hard to maintain the application if it was hosted on UC Berkeley servers even if the initial development was outsourced to an outside vendor.

We recommend using the XSLT processor that comes standard with the PHP XSL extension, Sablotron. Sablotron is an open-source XML toolkit implementing XSLT 1.0, DOM Level2 and XPath 1.0. As this processor has not been tested, if it does not meet the requirements for quick transformations, we recommend either the Xalan or Saxon 6.5.3 (which both implement XSLT 1.0 and XPath 1.0) processors.

Every file should start with a comment block describing its purpose, version, author, and contain a copyright message. the comment block should be in the style below.

/*
** File: test
** Description:  This is a test program
** Version: 1.0
** Created: 1/1/2000
** Author: Leon Atkinson
** Email: leon@clearink.com
**
** Copyright (c) 2003 Whichever.  All rights reserved.
*/

Every function should have a block comment specifying name, input/output, and what the function does.

/*
** Function: doAdd
** Input:  INTEGER a, INTEGER b
** Output: INTEGER
** Description:  Adds two integers
*/
function doAdd($a, $b)
{
	return(a+b);
}

Ideally, every while, if, for or similar block of code should be preceded by a comment explaining what happens in the block.

// get input from user char by char
while(getInput($inputChar))
{
	storeChar($inputChar);
}

Explain sections of code that aren't obvious.

//TAB is ASCII 9
define(TAB, 9);

// change tabs to spaces in userName
while($index=0; $index < count($userName); $index++)
{
	$userName[$index] = ereg_replace(TAB, " ", $userName[$index]);
}

As previously stated, functions should have a comment block explaining what they do and their input/output. The function block should align starting at one tab from the left margin unless the function is part of an class definition. Opening and closing braces should also be one tab from the left margin. The body of the function should be indented two tabs.

<?php
	/*
	** doAdd
	** Adds two integers
	** Input:  $a, $b
	** Output: sum of $a and $b
	*/
	function doAdd($a, $b)
	{
		return(a+b);
	}
?>

Flow control primitives (if, while, for, ...) should be compound statements, even if they only contain one instruction. Like functions, compound statements should have opening braces that start at column zero relative to scope. Code within the braces forms a new scope and should be indented.

// tell the user if a is equal to ten
if($a==10)
{
	printf("a is ten.\n");
}
else
{
	printf("a is not ten.\n");
}

The names of variables, constants, and functions are to begin with a lowercase letter. In names which con-sist of more than one word, the words are written together and each word starts with an uppercase letter.

Values that are treated as constants, that is not changed by the program, should be declared in the beginning of the scope in which they are used. In PHP this is done with the define function. Each of these constants should be paired with a comment that explains use. They should be named exclusively with uppercase letters, with underscores to separate words. You should use constants in place of any arbitrary values to improve readability. Example // maximum length of a name to accept define(“MAX_NAME_LENGTH”, 32); print(“Maximum name length is “ . MAX_NAME_LENGTH);

Variables are to be declared with the smallest possible scope. This means using function parameters when it’s appropriate.

Lines should not exceed 78 characters. Break long lines at common separators and align the fragments in an indented block.

if(($size < 0) OR
	($size > max_size) OR
	(isSizeInvalid($size))) 
{
	print("Invalid size");
}

Following are idioms you ought to use when appropriate. Often there are multiple ways to perform a task. Using an idiom will make the code instantly familiar.

//print all address fields
reset($AddressInfo);
while(list($key, $value) = each($AddressInfo))
{
	print("$key is $value<br>\n");
}