Useful PHP resources

PHP Manual
The manual consists primarily of a function reference, but also contains a language reference, explanations of some of PHP's major features, and other supplemental information.
URL: http://php.net/manual/

Recommended PHP Reading List
This list of recommended reading material on PHP is compiled from a variety of online sources by Web application developers at IBM's Global Production Services. An comprehensive list, despite the fact that the database integration material is focused DB2
URL: http://www-128.ibm.com/developerworks/opensource/library/os-php-read/

A Few Tips for Writing Useful Libraries in PHP
From the author of MagpieRSS is this excellent article on best practices when designing, coding and supporting software libraries written in PHP (or any language pretty much). Packed with 20 tips, and lots of examples and insights, it's well worth a read.
URL: http://laughingmeme.org/articles/2003/08/05/a-few-tips-for-writing-us

Zend Developer Zone
An online community for professional PHP developers, the Zone is a collection of news, articles, tutorials and examples, and provides the community with an interactive forum to promote best practices and methods for using PHP in real world applications.
URL: http://devzone.zend.com/

SafeHTML
If you're planning on rolling your own commenting system that accepts markup from a form, then you had best be careful about XSS and similar security issues. SafeHTML is a parser that will strip all potentially dangerous content from any untrusted source.
URL: http://pixel-apes.com/safehtml/

Symfony
Built from Mojavi (Model View Controller), Propel (object-relational mapping), Creole (database abstraction) and inspired by Rails, Symfony is an open-source PHP5 MVC framework designed to quickly create and easily maintain enterprise Web applications.
URL :http://www.symfony-project.com/

Duck Soup
A Technorati API library with support for CosmosQuery, SearchQuery, GetInfoQuery, OutboundQuery, BlogInfoQuery, TagQuery, TopTags, AttentionQuery and KeyInfo. Ducksoup can interact with Technorati, perform queries and produce the data in organized trees.
URL: http://kailashnadh.name/ducksoup/

dBug
dBug is a PHP class that displays structured information about a variable in a colored, tabular format. Simply put, it's PHP's var_dump function on steroids. With a name like dbug, all I can say is why didn't I think of that! (dbrowse, dcal, drx, hmm...).
URL: http://dbug.ospinto.com/

Moodle
Moodle is an open-source course management system designed using sound pedagogical principles with the goal of helping educators create effective online learning communities. It can scale from anywhere a single-teacher site to a 40,000-student University.
URL: http://moodle.org/

PHPUnit
Based on JUnit for Java, PHPUnit is an open-source framework for test-driven development with the PHP programming language. This is the online/ebook version of the same from O'Reilly and this author. PHP 5 is recommended, though you can get by with PHP.
URL: http://phpunit.de/pocket_guide/2.3/en/

Debugging Techniques for PHP Programmers
This article details various methods for debugging PHP applications, including turning on error reporting in Apache and PHP, and by placing strategic print statements to locate bugs in a sample PHP script. Also introduces PHPEclipse and DBG for Eclipse.
URL: http://www-128.ibm.com/developerworks/opensource/library/os-debug/

WASP
Web Application Structure for PHP is a powerful MVC Web application framework built from the ground up in pure Object Oriented PHP 5. WASP allows Web developers to make great applications with more fun and less code, but in the familiar playground of PHP.
URL: http://wasp.sourceforge.net/content/

MediaWiki
If you're looking for a Wiki package written in PHP, then look no further than MediaWiki, a free implementation developed by the fine folks at Wikipedia and related sites. MediaWiki uses a MySQL database backend and installation is incredibly simple.
URL: http://mediawiki.org/wiki/MediaWiki

Atlanta PHP
Right up there with the best localized PHP developer community groups like NYPHP (New York) and PDX (Portland, OR) is Atlanta PHP. A great source for news, job openings and more. If you live in the Southeast, or are planning a move, look up Matt or Ben.
URL: http://atlphp.org/

Joomla!
From the same team that brought you the award winning Mambo CMS, OSM has taken their final stable version of Mambo (4.5.2.3), given it a spring clean and named it Joomla! 1.0, and it includes several features that were going to be released in Joomla! 1.1.
URL: http://joomla.org/

PHundamentals
From the NYPHP, one of the largest and most active PHP user groups, is this growing series of articles contributed by many of the diverse members of the PHP development community. Categories include AMP setup, site development and programming techniques.
URL: http://www.nyphp.org/phundamentals/

Drupal
Drupal is a multi-platform Content Management System (CMS) that supports both MySQL and PostgreSQL backends, with a database abstraction layer that can be extended to add other RDBMS. Version 4.6+ is PHP 5 compatible. Too many features to enumerate here.
URL: http://drupal.org/

The Horde Project
An object-oriented, open-source, open-standards framework for developing Web applications in PHP, as well as a set of existing applications including IMP, Turba, Kronolith, Nag and Mnemo. Phew! Supports localization features such as Unicode and RTL text.
URL: http://horde.org/

Savant
A lightweight PHP templating system which, unlike Smarty, does not compile your templates or use a separate markup syntax. Instead, it uses normal PHP syntax, so there is no parsing overhead involved. Additional features include an OOP plugin/filter API.
URL: http://phpsavant.com/yawiki/

PHP Regular Expression Clinic
This PDF slideshow format tutorial on the PHP PCRE extension is an outstanding resource for developers new to regular expressions. Exceptionally well designed, the presentation requires no speaker to inform the reader. Over 200 pages, with many examples.

Mambo
Mambo is probably the most popular open-source Content Management System (CMS) on the Web. Built on Apache, MySQL, and of course PHP. Runs on Linux, FreeBSD and Mac OS X. SourceForge hosts several bundled distributions of Apache/MySQL/PHP plus the CMS.

PHP Cookbook
Why reinvent the wheel? A collaborative collection of techniques, code examples and comments from the PHP development community. Anyone can contribute, or submit comments and improvements. Not to be confused with the O'Reilly books of the same name.
URL: http://aspn.activestate.com/ASPN/Cookbook/PHP

Tuning Apache and PHP for Speed on Unix
To supplement John's detailed Optimizing PHP analysis, is this collection of tips, howtos and links for getting the most out of your PHP and Apache installation. My suggestion: pass arrays and objects by reference, both into and returning from functions.
URL: http://phplens.com/phpeverywhere/?q=node/view/8

Markdown Extra
An enhanced version of PHP Markdown, of which I am a huge fan. This release includes support for inline HTML, block-level elements, definition lists, tables, and new rules for emphasis and backslash escapes. Kudos to Michel, nice work!
URL: http://michelf.com/projects/php-markdown/extra/

PHP Editors
A mega-resource site that focuses on reviewing PHP editors and IDEs. In truth, that's just the tip of the iceberg. There's also news, templates, tutorials and articles, resources, book reviews, forums, programming contests, and jobs including freelancing.
URL: http://www.php-editors.com/

Vanilla
Is an open-source PHP/MySQL forum package. Several things make this product stand out: an intuitive and nicely styled, extensible interface, and it is built with semantic and valid XHTML markup free of tables that separates both presentation and behavior.
URL: http://getvanilla.com/

Advanced PHP Resources
A list of resources intended to improve your PHP programming techniques, including such things as OOP and PHP, development tools, class libraries, repositories and extensions, frameworks, recommended reading, PHP5, and communities and blogs.
URL: http://www.sitepoint.com/forums/showthread.php?t=78687

Comfortable PHP Editing with VIM
And here's an example of phpm in action. If you use Vim, this article will explain how you can set up the editor so one keystroke will display the PHP syntax for function under your cursor. But that's only the start, many more productivity tricks here.
URL: http://schlitt.info/applications/blog/index.php?/archives/331-Comfortable-PHP-editing-with-VIM-3.html

phpm: The PHP Manual Revisited
Now this is clever. What this guy has done is taken the XML source to the PHP manual, extracted out the syntax of all the function calls, and written a PHP shell script so you can access this information without having to go to a browser to look them up.
URL: http://phpvolcano.com/articles/manual/

Regular Expressions Tutorial
And specifically the Perl regular expression (PCRE) functions in PHP. Which are the ones everyone should be using. The expression syntax is more powerful than the ereg() functions, and they are much faster. But please, only use regex when you need to!
URL: httL://weblogtoolscollection.com/regex/regex.php

phpXplorer
An open-source file management system written in PHP. It enables you to work on a remote file system through a Web browser. There are dialogs for editing HTML, PHP, image, Apache, compressed and email files. And its modular design makes it extensible.
URL: http://phpxplorer.org/phpXplorer/webIndex.php

PHP Filters
Because data originating from an end-user is highly insecure, it should be treated with the utmost care. In the Perl world, this is referred to as "taint checking." PHP Filters is a collection of functions for doing just this: sanitizing user inputs.
URL: http://owasp.org/software/labs/phpfilters.html

PHP SmartyPants
Another PHP port from Michel, this time it's SmartyPants. This text filter converts ASCII punctuation characters to their corresponding typographic entities such as curly quotes, en/em dashes and ellipsis. Use with Smarty, WordPress, or your own programs.
URL: http://michelf.com/projects/php-smartypants/

Scuttle
Scuttle is an open-source del.icio.us clone written in PHP with a MySQL backend. Use it as your private bookmark manager, share your links with everyone or selected members, or download and incorporate the software into your own site or application.
URL: http://sourceforge.net/projects/scuttle/

Yellow Duck
An object-oriented framework for developing PHP applications which uses Smarty templates for its presentation layer. Other features include support for RSS and Atom feeds, multiple database backends, XML-RPC, authentication, shopping carts and more.
URL: http://yellowduck.be/ydf/

PHP Magazine
An outstanding international online and print magazine for PHP professionals. News, articles, columns, book reviews, discussion forums and more. Available on newsstands, in CD and high-quality PDF. All source code to the articles is available online.
URL: http://phpmag.net/

phpWebSite
An open-souce CMS system designed for community-driven Web sites. Generates valid XHTML 1.0 markup, and meets the W3C's Web Accessibility Initiative requirements. Web-based administration allows for easy maintenance, and is extensible via modules.
URL: http://phpwebsite.appstate.edu/

Hotscripts: PHP
A mind-boggling array of resources for PHP users, developers and programmers. Categories include books, scripts (of course), articles, communities, software and servers, text processing, tips and tutorials, and Web sites. Each one rated by visitors.
URL: http://hotscripts.com/PHP/?RID=N370426

CakePHP
Ruby on Rails is all the rage these days, and the author calls his OOP PHP rapid application framework a Rails "rip-off." The problem with Ruby is most hosting companies don't support it. Worth a look, but I would like to see it mature a little more.
URL: http://cakephp.org/

eAccelerator
This is the new incarnation of Turck MMCache, picked by Frank Alcantara after the original developer, Dmitry Stogov, stopped supporting MMCache. Version 0.9.3 final was just released last month. I've had great success with the original in the past.
URL: http://eaccelerator.sourceforge.net/

Burning the Bulb Brighter
And you have burned so very, very brightly, Roy. A detailed discussion of PHP accelerators and optimizers, including APC, PHPA, Zend Optimizer and Turck MMCache (now eAccelerator). The original developer of Turck is now working for Zend.
URL: http://www.linux-mag.com/content/view/1676/2189/

phpSurveyor
A PHP code library for developing, deploying, collecting and displaying the results of online surveys. A distributed token feature allows you to restrict only registered users access to a survey, so the results aren't skewed. Uses a MySQL backend.
URL: http://phpsurveyor.sourceforge.net/

Serendipity
A blog system implemented in PHP. Features include (but not limited to!) standards compliance, an enhanced editing interface, threaded and moderated commenting, dynamic caching, trackback and ping, skins and plugins, multiple database backends...
URL: http://s9y.org/

BestCatalog: PHP
There's no way I can list every resource out there, so if you still can't find what you're looking for after searching drx, you may want to try this PHP resources directory.
URL: http://bestcatalog.net/category575626.html

phpPatterns
Harry seems to have stopped updating this site recently, but don't let that shy you away. There are a ton of good articles and tutorials here organized into categories so you can locate titles that interest you quickly.
URL: http://phppatterns.com/index.php/link/category/1/

PHP Functions Essential Reference
Online companion to the outstanding reference book. Many functions explained, and more importantly with usage examples that are cross-referenced with similar functions so navigating is easy. My only complaint is the list needs updating.
URL: http://phpdig.net/ref/

phpFlickr
A PHP class library that acts as complete and intuitive wrapper to the Flickr API. All Flickr methods are supported, easy to install and includes caching support. Download available on SourceForge. Nice work Dan, I'll have to give this a try soon.
URL: http://phpflickr.com/

PhpWiki
A clone of the original WikiWikiWeb in PHP. Quickly set-up a site where anyone can add or edit pages to form a collaborative resource. "The Universe tends toward chaos. The Universe tends toward Wiki" Nicely done, hosted by SourceForge. URI:http://phpwiki.sourceforge.net/phpwiki/

A Decade of PHP
Wow, unbelievable that so much time has flown by. I remember writing whole systems back then with Perl, CGI and flat files. I was poking around with ePerl when PHP came out, and then MySQL. What would things be like now without them? URI:http://www.phpdeveloper.org/index/3235

Developer Tutorials: PHP
A large collection of howto-style tutorials for less experienced PHP programmers. Similar in concept to Lockergnome, (which gags me to even mention) without all the ads. Lots of other resources including mirrored copies of the PHP and Pear manuals.
URL: http://developertutorials.com/tutorials/php/

Creating and Consuming Web Services With PHP
This article compares and contrasts three methods of using PHP to query Web services: XML-RPC, SOAP and REST. I prefer the power of SOAP using the simplified NuSOAP library, which is how the search feature of the drx application is implemented.
URL: http://webservices.xml.com/pub/a/ws/2004/03/24/phpws.html

A Howto on Optimizing PHP
An excellent, and very detailed, article on optimizing your PHP applications. Topics include the most common bottlenecks, tuning your hardware, Web server and database engine, opcode and output caching, and benchmarking. Study this one carefully.
URL: http://phplens.com/lens/php-book/optimizing-debugging-php.php

Freetag
An open-source tagging/folksonomy module for PHP/MySQL. By using a simple set of tables the identify users, and a set of tags that are uniquely indexed by integers, you can quickly add folksonomy tagging to your application with this PHP module.
URL: http://getluky.net/freetag/

A Programmer's Introduction to PHP 4.0
Free online addition of the book from Apress, but only available as a (large) PDF. So if you're interested, I recommend you get or upgrade to the latest Adobe Acrobat Reader. Which, as of this review, is version 7.0, and includes many enhancements.
URL: http://apress.com/free/

Programming: PHP
PHP is a scripting language designed to fill the gap between Server Side Includes (SSI) and Perl, intended largely for the web environment.
URL: http://wikibooks.org/wiki/Programming:PHP

PHP Trackback
An easy to use PHP class that implements full trackback capabilities for your custom blog. Can act as both a ping server and client. Seeds pages with embedded RDF metadata for auto-discovery, and extracts trackback ping URIs from any source string.

PHP Security Guide
A detailed guide to securing your PHP applications. Topics include register globals, data filtering, error reporting, forms processing, securing database connections and SQL injection attacks, and session data and shared hosting environments.
URL: http://phpsec.org/projects/guide/

PHP Markdown
A port of John Gruber's Markdown, a simple yet effective plain text markup language. Designed as a plug-in for Wordpress or bBlog, a Textile replacement, an enhancement to the Smarty template engine, and is very easy to use in your own programs.
URL: http://michelf.com/projects/php-markdown/

PHP Cache Control
Fred describes a simple scheme for caching dynamic PHP documents. Works only for documents based on the script's modified timestamp, you will need another approach if the content is extracted from a DB for example. I recommend adding an Etag header.
URL: http://ontosys.com/php/cache.html

PHP RSS Parser
If you're not a programmer, or just plain lazy (hey, who isn't sometimes!), this tool will convert an RSS feed into PHP code for inclusion into your site. As in automatically, every time the feed updates so does your content. Pretty sweet.
URL: http://globalsyndication.com/rss-parser

PHP Cookbook
Anyway, like I was sayin', PHP is the fruit of the Web. You can BBQ it, boil it, bake it, fry it. Dey's uh, PHP-kabobs, PHP creole, PHP gumbo, pineapple PHP, coconut PHP, PHP soup, PHP stew... Over 250 "recipes" (source code) from the book.
URL: http://www.oreilly.com/catalog/phpckbk/

The Hitchhiker's Guide to PHP
When a company like Oracle gives you its blessing, then you know you've hit the big-time. This seven part series kicks off with an introduction by Rasmus Lerdorf, the creator of PHP. His Tips and Tricks sidebar is worth the free admission alone.
URL: http://www.oracle.com/technology/pub/articles/php_experts/

PHP Tutorials
A PHP File Manager, dealing with errors, tree traversal, query strings, GD image library key codes for securing forms against spam bots, source code highlighting and more. Interesting site, worth the visit.
URL: http://aesthetic-theory.com/tutorials.php

PHP Development Center
More technology articles from Oracle. You know, that company, they have some sort of database thing? Demos of PHP running under the Oracle Application Server, installation guides, sample book chapters, and lots more.
URL: http://www.oracle.com/technology/tech/php/

Building a Blog with Dreamweaver, PHP and MySQL
I'm not a big fan of shrink wrap software, but the rest of this six part, and very detailed article is worth a read if you're thinking of rolling your own blogging software. Advanced features include search, multiple users and administration.

PHP Buzz
Outstanding community/blogger site from Artima Developer. They also have categories for Design, Java, Linux, MacOS, Open Source, Perl, Python, Ruby, XML and a few others I won't mention. RSS feeds of new posts, impressive blogroll as well.
URL: http://www.artima.com/buzz/community.jsp?forum=

PHP Community
Anyone can join, contribute, post questions, get answers, solve problems, browse the forums, learn... Includes member blogs, a Wiki, articles and tutorials. Nice site.
URL: http://phpcommunity.org/

Shiflett.org
Security for Web-based applications is an important issue, and Chris is a recognized expert in the field, as well as an accomplished programmer and author. This is his professional blog (see also his consultancy: Brain Bulb).
URL: http://shiflett.org/

Planet PHP
Planet PHP is community news/blog site which aggregates posts from many sources. The blogroll is very impressive, and you'll find lots of additional open-source resources in the "Planetarium." Go network!
URL: http://www.planet-php.net/

PHP REST SQL
Paul has crafted an interesting PHP class for interacting with a MySQL database using HTTP and a RESTful interface. Without some serious security considerations, I would avoid allowing modifications. But a dynamic RSS service leaps to mind.
URL: http://phprestsql.sourceforge.net/

PHP DevCenter
PHP articles, news, reviews, "recipe of the day", PHP and MySQL, Web Services, debugging, security, related and affiliate sites, and much more. From the O'Reilly Network.
URL: http://www.onlamp.com/php/

Searching with PHP and MySQL
For small to medium-sized Web sites, here's a technique for building your own search engine from open-source tools. Plenty of detail and code examples in this well written article. Follow-up piece on highlighting, and PDF versions for printing.
URL: http://iamcal.com/publish/articles/php/search/

Coppermine Photo Gallery
Your own personal Flickr? Build a photo gallery with open-source software using Apache, PHP, MySQL and either GD or ImageMagik. The feature-set is impressive, and always growing, I recommended trying the demo first. Very nicely done project!
URL: http://coppermine.sourceforge.net/

Accelerating PHP Applications
A really well done presentation on optimizing your PHP applications. Includes tips for install/compile/config (PHP and Apache server), cache and compression, file I/O, sessions, database optimization, etc.
URL: http://talks.php.net/show/acc_php/1

PHP Cheat Sheet
Designed for printing and storing near your desk, this handy quick reference includes a frequently used function list, superglobal variables, date formats, function arguments, fopen() file modes and regular expression syntax.
URL: http://www.ilovejackdaniels.com/php/php-cheat-sheet/

Dev Shed: PHP
PHP help, tutorials, articles, code samples, and other resources. Features in-house authors, freelance writers, and several exclusive publishing relationships. .
URL: http://www.devshed.com/c/b/PHP/

Smarty Template Engine
A framework for PHP programmers and Web site designers that allows the separation of application logic and content from its presentation. Part of the PHP Group (php.net).
URL: http://smarty.php.net/

XOOPS
XOOPS (Extensible Object Oriented Portal System) is a dynamic Web Content Management System (CMS) written in PHP and is driven by a MySQL backend. Primarily designed for Web communities, it is modular, object-oriented and supports themes.
http://www.xoops.org/Authorhttp://www.xoops.org/

PHP Developer's Network
A large categorized set of discussion forums for getting and sharing information about PHP development. Includes code snippets, databases, Linux and Apache and much more.
URL: http://forums.devnetwork.net/

PEAR: PHP Extension and Application Repository
The code in PEAR is partitioned in "packages". Each package is a separate project with its own development team, version number, release cycle, documentation and a defined relation to other packages (including dependencies).
URL: http://pear.php.net/

php.faqts
PHP frequently asked questions and tips.
URL: http://faqts.com/knowledge_base/index.phtml/fid/51

PHPBuilder.com
PHP tutorials, templates, manuals, content management systems, scripts, classes and more for the PHP developer.
URL: http://www.phpbuilder.com/

New York PHP
You don't have to be a New Yorker to benefit from this organization. This SIG has a very active mailing list, and many other resources for PHP and other Open Source programmers.
URL: http://www.nyphp.org/

Zend Code Gallery
Categorized listings of PHP tips, code examples and applications.
URL: http://zend.com/codex.php