PHP based forum software (O-Z):
OvBB | Free
Distributed under an MIT-type open source license, OvBB is a light-weight and fast bulletin board system that mimics vBulletin 2.x.x in both look and behavior while incorporating new advanced features and functionality. OvBB is written in PHP and is powered by MySQL.
Phorum | Free
Phorum is a web based message board written in PHP. Phorum is designed with high-availability and visitor ease of use in mind. Features such as mailing list integration, easy customization and simple installation make Phorum a powerful add-in to
phpBB | Free
phpBB is a high powered, fully scalable, and highly customizable Open Source bulletin board package. phpBB has a user-friendly interface, simple and straightforward administration panel, and helpful FAQ. Based on the powerful PHP server language and your choice of MySQL, MS-SQL, PostgreSQL or Access/ODBC database servers, phpBB is the ideal free community solution for all web sites.
punBB | Free
PunBB is a fast and lightweight PHP-powered discussion board. It is released under the GNU General Public License. Its primary goals are to be faster, smaller and less graphically intensive as compared to other discussion boards. PunBB has fewer features than many other discussion boards, but is generally faster and outputs smaller, semantically correct
Quezza | Free
Quezza is a free PHP-powered forum based on phpBB.
Quicksilver Forums | Free
Quicksilver Forums is a fast, feature rich bulletin board system written in PHP and MySQL. It is fully object oriented and optimized for speed, ease of use, and easy modifications. QSF checks all inputs though a common interface which drastically reduces the chances of exploitable bugs. Powerful and flexible skinning engine makes giving your board a new look very simple. Advanced permissions system allows for fine grained group and user permissions. Released under the GNU General Public License. Based on the popular MercuryBoard software.
Shiichan | Free
Shiichan is an anonymous bulletin board system, thus it allows for pseudonymous "registration"-like features without storing any user information in a database. Most importantly, it makes it possible to create boards without having to tinker with the filesystem. It is written in PHP and the source code has been released under the GNU GPL.
SMF | Free
Elegant. Effective. Powerful. Free. SMF is all of the above. SMF is a next-generation community software package and is jam-packed with features, while at the same time having a minimal impact on resources. And, yes, it is free.
Sylphagora | Free
Sylphagora is a free internet forum system implemented in PHP and MySQL. It is a fairly modest, threaded board system that, although it lacks a lot of features found in other board systems, is lightweight and fast.
tForum | Free
tForum is a versatile and easy to edit forum, with lots of ready to add modifications. It is free software created by the collaborating forces of the webmasters that uses it.
UBB.threads | $299 standard license, $125 renewal
UBB.threads (formerly WWWThreads) is an Internet forum software package written by Rick Baker. Written with PHP using a MySQL database backend, it is comparable to other forum software such as phpBB, vBulletin and MyBulletinBoard.
UNB | Free
The Unclassified NewsBoard (short UN is an open-source, PHP-based internet bulletin board system, mostly like those you may already know. But the difference is in a lot of details that make your life with this board, both as administrator and user, much easier. You’ll be surprised how easy things can be and how fast you can work with such a system! The Unclassified NewsBoard has a lot of innovative features the world has never seen before in this way.
UseBB | Free
UseBB is a light and Open Source PHP and MySQL based forum package, distributed freely under the GPL license. Developed with simplicity and usability in mind, UseBB is ideal for small to medium sized websites which need a clear and efficient forum package.
Vanilla | Free
With Vanilla we wanted to break the mold created and followed by just about every other forum on the web. We sat down and thought about what we liked, and more importantly, what we didn't like about web forums. We wanted emphasis on the discussions rather than the statistics. We wanted to stop using MSN or AIM to send secret messages to other forum members; We wanted to be able to save the common searches. Basically, we wanted the thing to work for us instead of against us. Most importantly we wanted it to be free and we wanted it to run on just about every web server out there. So, Vanilla is a PHP / MySQL solution that is 100% open-source. You can take it and alter it and use it free of charge.
vBulletin | $85 p.a. / $160 lifetime | * Forum Software this site uses
vBulletin is a powerful, scalable and fully customizable forums package for your web site. It has been written using the Web's quickest-growing scripting language; PHP, and is complemented with a highly efficient and ultra fast back-end database engine built using MySQL. vBulletin is the ideal community solution for all medium-to-large sites.
W-Agora | Free
W-Agora is a WEB based application developed using PHP and MySQL. This solid back end technology, also known as LAMP (Linux Apache Mysql PHP) allow the community to provide fast and reliable applications. W-Agora is probably one of the most customizable package from its category. It is designed so it can be easily customizable through a Web browser and the use of templates. eg. it can be used as a BBS, guestbook, download area, a photo gallery or a news publishing system.
WSN Forum | Free / $48.50
WSN Forum is an advanced PHP/MySQL discussion forum script, designed to serve the needs of forum admins who want maximal control over their forums.
XMB | Free
XMB provides forum administrators with one of the highest performing, most secure forums available. XMB is highly tuned for high volume web sites, with nearly all end-user pages requiring no more than 15 SQL queries. All mainstream high frequency queries use indexes, have limits, and are tuned to work efficiently with MySQL 4.0.x and later XMB optimizes output to pump the minimum amount of data to display a page, and attachments are cache friendly.