Web Apps
WordPress
WordPress started in 2003 with a single bit of code to enhance the typography of everyday writing and with fewer users than you can count on your fingers and toes. Since then it has grown to be the largest self-hosted blogging tool in the world, used on hundreds of thousands of sites and seen by tens of millions of people every day.
http://wordpress.org/
eGroupWare
eGroupWare is a free enterprise ready groupware software for your network. It enables you to manage contacts, appointments, todos and many more for your business.
http://www.egroupware.org/
WebCalendar
WebCalendar is a PHP-based calendar application that can be configured as a single-user calendar, a multi-user calendar for groups of users, or as an event calendar viewable by visitors.
http://www.k5n.us/webcalendar.php
CSLH
CSLH is a live support system which is free for websites and multi-user multi-operator multi-department and open source.
http://www.craftysyntax.com/
Coppermine
Coppermine is a multi-purpose fully-featured and integrated web picture gallery script written in PHP using GD or ImageMagick as image library with a MySQL backend.
http://coppermine-gallery.net/
Advanced pool
Advanced Pool allows to easily create polls.
Gallery
Gallery is an open source web based photo album organizer. Gallery gives you an intuitive way to blend photo management seamlessly into your own website whether you're running a small personal site or a large community site.
http://gallery.menalto.com/
AutoIndex
Lightweight script that allows you to generate lists of files and folders on a generated webpage.
http://autoindex.sourceforge.net/
B2evolution
B2evolution is a free blog tool for the next generation of blogs. It includes all the features of traditional blog tools, and extends them with evolved features such as file & photo management, advanced skinning, multiple blogs support as well as detailed user permissions...
http://b2evolution.net/
Mambo
Mambo is a dynamic portal engine and content management system. The backend is very intuitive and fully customizable.
http://www.mamboserver.com/
OpenBiblio
OpenBiblio is an easy to use, automated library system written in PHP containing OPAC, circulation, cataloging, and staff administration functionality.
http://openbiblio.sourceforge.net/
BBClone
For each visitor BBClone counter can display: IP address, operating system, browser, referrer, visit date, page visits and number of visitors. staff administration functionality.
http://www.bbclone.de/
SiteFrame
Siteframe is a flexible, extensible community content-management system that supports images and multiple document types.
http://siteframe.org/
OsCommerce
OsCommerce features a rich set of out-of-the-box online shopping cart functionality that allows store owners to setup, run, and maintain their online stores with minimum effort and with no costs, fees, or limitations involved.
osCommerce has attracted the largest community for an e-commerce solution that consists of over 141,200 store owners and developers worldwide with add-ons being contributed on a daily basis. To date there are over 4,000 add-ons available that have been created by the community to extend the features of an osCommerce online store.
http://www.oscommerce.com/
DocFaQ
DocFAQ provides users the ability to administer documents. It helps you index the documents of your website.
http://sdx.net/faq/index.php/DocFAQ_Installation
PHPDig
PhpDig is a Web spider and search engine written in PHP, using a MySQL database and flat files. It builds a glossary with words found in indexed static and dynamic content.
http://www.phpdig.net/
Owl
Owl is a multi user document repository (knowledgebase) system written in PHP4 for publishing files/documents onto the web for a corporation, small business, group of people, or just for yourself.
http://owl.sourceforge.net/
PHPWebSite
PHPWebsite is a complete content management system. The generated code is XHTML valid.
http://www.phpwebsitemanual.com/
phpWiki
An open source implementation of a WikiWikiWeb in PHP.
http://phpwiki.sourceforge.net/
phpAdsnew
Openads is the world's most popular adserver with the the web's largest community of ad space owners. Tens of thousands of websites use Openads to make money from online advertising.
http://www.phpadsnew.com/two/
PostNuke
The Postnuke Content Management System offers full CSS support and HTML 4.01 transitional compliance throughout.
http://www.postnuke.com/
phpBB
Since its creation in 2000, phpBB has become the most widely used Open Source forum solution. phpBB has an easy to use administration panel and a user friendly installation process, which allows you to have a forum set up in minutes.With a large and highly customizable set of key features coupled with a standard compliant interface, phpBB will grow with, and compliment your website.
http://www.phpbb.com/
Typo
A unique system that features dynamic graphical menus, different templates based on browser type, automatic image scaling and user groups.
http://typo3.com/
UebiMiau
UebiMiau is a simple, yet efficient mail reader (webmail) supporting both IMAP and POP3 without dependence of any PHP's extra modules or database
http://www.uebimiau.org/
phpBook
phpBook is a free non-commercial guestbook utility for your personal projects. phpbook is fast, good-looking and also secure and has some small functions to prevent spamming.
WebShopManager
Turn Key Online Application with Free Upgrades; No Software to Purchase or Install; Control all Your Selling Needs; Fast & Easy to Get Started.
http://webshopmanager.com/
Tutos
TUTOS is a tool to manage the organizational needs of small groups, teams, departments.
http://www.tutos.org/homepage/index.html
TellMe
Tellme is a collection of network utilities written in PHP.
http://www.craftysyntax.com/
XRMS
XRMS is a fully-integrated suite of web-based tools for Customer Relationship Management (CRM), Sales Force Automation (SFA), and Business Intelligence (BI) tools.
http://sourceforge.net/projects/xrms/
phpSurveyor
phpsurveyor is an Open Source PHP web application to develop, publish and collect responses to online & offline surveys.
http://www.phpsurveyor.org/
pLog
PLog is a extensible and easy to use logging library for PHP5. It supports different log-targets (file, database, syslog, network).