Free-PHP

A modular Bulletin Board System based on PHP 5 and MySQL 4+. [Open source, GPL]

An open-source, web-based, threaded forum system written in PHP, supporting nested posts and forums.

Template-driven PHP/MySQL forum software developed by the creators of WordPress. [Open source, GPL]

Usenet style threaded discussion, multiple forums, multiple languages, automatic archiving, printable pages, and message voting.

A simple, easy to use message board system. It supports single or multiple forums, user registration and anonymous posting, and forum administrators. ccForum is written in PHP and is based on a MySQL database. [Open source, GPL]

A simple to use PHP forum package.

Very feature-rich PHP forum system with MySQL/PostgreSQL backend.

A multi-thread customisablebulletin board messaging system. It uses PHP and either MySQL or PostgreSQL database. [Freeware]

Ikonboard's PHP version. It supports all CGI version's features and it's free. A free registration is required to download the script.

Open-source forum software in PHP.

A simple message board for those who don't want or need large forums. Supports smileys, e-mail notification and more. [Freeware]

Bulletin board written in object-oriented PHP4 with a MySQL database backend.

Small, fast and free discussion board system written in PHP, can be based on any database supported by PHP (including mySQL and PostgreSQL).

Coded in PHP and backed by mySQL. Free

Oneiric is a free (GNU/GPL) PHP Bulletin Board with a mySQL backend.

A light-weight and fast bulletin board system that mimics vBulletin 2 in both look and behavior while incorporating new features and functionality. [Open source, MIT]

A free threaded, web-based bulletin board system written in PHP with a variety of backend database option available.

A free thread-oriented, XML-based news forum. No database required.

A message board system implementing a clean linear model. [Open source, GPL]

Lightweight PHP discussion board with MySQL/PostgreSQL database backend.

A fast, and search engine friendly forum software written in PHP/MySQL. [Open source]

Template designer for phpBB, vBulletin, IPB software.

A community software package with themes, fast message database, secure file-attaching system, and mod installation manager. [Freeware]

Forum software written in PHP with a MySQL backend.

A PHP forum software to a higher level YABBSE based concept radically modified and customized for free.

An open source PHP-based database-free very small and simple forum with Multi-language, multi-skin, avatar uploading support.

A free threaded message board script written in PHP with a MySQL backend.

Unicode-supporting PHP/MySQL forum software that produces standard XHTML and CSS. [Open source, GPL]

A PHP/MySQL bulletin board package designed for small to medium sized web sites. [Open source, GPL]

PHP/MySQL forum software with multilingual support and more than 100 plug-ins. [Open source, GPL]

An easy-to-use and scaleable open source bulletin board system that enables you to easily create, manage, and promote your online community.

Free forum written in PHP. It has also a guestbook, a download area, a photo gallery and a news publisher feature. It uses MySql as database.

Interoperable (vBulletin, phpBB2 and IPB) Web/WAP Discussion Forums for Cell phones, PDAs and other handheld devices.

A very simple discussion board program written in PHP. It doesn't use any SQL database.

WowBB offers features such as auto install/upgrade, a WYSIWYG editor with integrated spell-checker, auto time zone detection and smart caching. Requires PHP and MySQL.

PHP/MySQL forum software that supports themes, BB code, and instant messaging. [Open source, GPL]

Free forums and professional message board and forum software for personal or business use.

A PHP/MySQL port of Yet another Bulletin Board (YaBB) 1 Gold (see above).