I am gonna post here some the very useful php libraries and classes which will come so handy during coding. You might run into various requirements which is why i compiled these php components. All the php libraries listed below is free software and can be downloaded in the original authors website.
FPDF
FDPF is a free PHP library create PDF files with pure PHP.
PHP Mailer
http://phpmailer.codeworxtech.com/
PHP Mailer is a free class to send emails using PHP. It supports html and plain text email formats, including mail() and SMTP functions.
Autosuggest Search
http://woork.blogspot.com/2008/03/php-components-autosuggest.html
PHP component to implement auto suggest feature in your textbox using MySQL.
ADODB Database Abstraction Library
ADOdb is a database abstraction library for PHP designed for speed and portability. It supports number of databases including mssql, mysql, oracle, postgresql, and much more ..
reCaptcha
Free PHP library to implement antibot captcha in your website for registrations. It is free service and works well with php.
phpThumb
http://phpthumb.sourceforge.net/
Very useful and light weight image manipulation library in PHP for generating thumbs in your website.
pChart
http://pchart.sourceforge.net/
A free php chart library to create numerous varieties of charts. Charts can be constructed from sql, csv, and from database datasets
Magpie RSS Parser
http://magpierss.sourceforge.net/
A PHP parser to extract fields from your RSS feed. It is easy to use without any difficulties.
PHP Text to Image
http://www.phpinsider.com/php/code/str2img/
A useful class which writes a text or string to an image. Useful for hiding emails and for simple captchas. It can also output text inside an image at different angles.
Smarty
A very popular templating engine for PHP. It is fast, lightweight and optimized for speed.
OpenID Login Authentication
OpenID is a fastest and easiest code to implement login in your website. This zend tutorial might help for implementing openID
HTML Purifier
HTML purifier is an open source class for filtering mailicious and harmful XSS scripts. It is free library
jQuery
jQuery is a widely popular javascript library for event handling, animated transitions and interactions. It can be easily used with php for complex interactive web applications. Please see jquery PHP library to connect php to jquery
SAJAX
http://www.modernmethod.com/sajax/
Ajax framework for creating rich web applications. It easy to call PHP, Perl or Python functions from your webpages via JavaScriptYou. Alternatively, xajax which is as good as sajax.
UPU File Uploader
http://sourceforge.net/projects/upu/
UPU is a multiple file uploader class with progress bar. It is free software.
Univeral Feed Creator
Free PHP class which generates RSS and Atom feeds. Another useful class is Feed Creator where you can quickly create RSS feed from MySQL database.
phpLib
http://phplib.sourceforge.net/
object-oriented application development toolkit for PHP. It is a free software for php programmers and developers.
CakePHP
Rapid PHP development framework for web applications.
PHP Excel
Free spreadsheet engine library to read and write excel, pdf, csv and html formats.
GeSHi Syntax Highlighter
Geshi is a generic syntax code highlighter library supporting over 100 languages including PHP. Another alternative tool to highlight PHP code is phpCodeBeautifier
phpUserClass
Useful php library for user authentication and login management. It is a free open source project.
PHP Math Publisher
http://www.xm1math.net/phpmathpublisher/
PHP publishing system for publishing mathematical formulas. Each formulas are transformed into a image and it can be dynamically created. It works well in blogs, forums and with other content management applications.
PHP Image Upload & Crop
http://www.webmotionuk.co.uk/php-jquery-image-upload-and-crop/
PHP/JQuery image upload and cropping library. It needs GD library to be installed.
Smart Image Resizer
http://shiftingpixel.com/2008/03/03/smart-image-resizer/
Easy to use php class to crop and resize images on the fly.
GoogleMap API
http://www.phpinsider.com/php/code/GoogleMapAPI/
A library used for creating google maps using the Google Map public API. Features include multiple map markers, customizable icons, map directions built into info window, and sidebar generation.
IP to Country Lookup
http://www.eyesis.ca/projects/iplookup.html
Free php class to lookup ip address to country.
PHP Code Sniffer
http://matrix.squiz.net/developer/tools/php_cs
Useful library checks PHP code for programming violations and often used for testing PHP code practises.
