Communication Software for PHP
Elgg
Elgg is an award-winning open source social networking engine that provides a robust framework on which to build all kinds of social environments, from a campus wide social network for your university, school or college or an internal collaborative platform for your organization through to a brand-building communications tool for your company and its clients.
HumHub
HumHub is a free and open-source social network software and framework built to give you the tools to make communication and collaboration easy and successful. HumHub is designed to be lightweight, powerful and comes with an user-friendly interface that is easy to use both for users of the social network and administrators.
Community Builder
Community Builder (CB) is an extremely flexible and robust social networking solution for Joomla.
bbPress
bbPress is forum software from the creators of WordPress. With bbPress you can quickly setup a forum for asyncronous discussion and subscriptions for your WordPress-powered site.
phpBB
One of the world most popular, free, open-source and self-hosted forum software, written in PHP. With phpBB you can create communities that can be hosted with most hosting providers. The software package is built and designed from the ground up to to be extensible and provides customization option through themes and feature extensions through plugins. The extensive database of user-created extensions and styles database, easy of use, and the simple installation process has made phpBB a common choice among self-hosted forums and communities.
Invision Community
Invision Community is a leading platform for building vibrant communities with forums, eCommerce, content management, image galleries and more. With Invision Community, you can increase your brand or business customer loyalty, reduce support costs and drive sales by building a vibrant online community.
Vanilla
Create an online community that your customers will love. Vanilla's forum software is used by top brands to engage customers, drive loyalty and reduce support costs. The software is provided free and open-source as a self-hosted solution and can be bought by businesses and enterprises as a managed and hosted solution.
Flarum
A free and open-source modern forum software written in PHP. With Flarum you can eaisly setup your own discussion froum and host it online.
Simple Machines Forum
Simple Machines Forum or SMF in short is a free and open-source forum software. SMF can be used to build your own online community that you self-host on a host of your choice. Simple Machines Forum comes packed with features for customization, extension and management of your community. The template engine puts you in control of the design of your community. The plugin architecture makes it easy to extend and provide further feautres though third-party built packages.
LayerBB
LayerBB is a small yet feature rich, free and open-source community software written in PHP. LayerBB enables you to quickly and easily start your own community while providing great flexibility and customisability.