NodeBB!

Discourse is an open source discussion platform built for the next decade of the Internet. A modern forum, everything's been redesigned to be easy.

Flarum is free, open-source forum software with a focus on simplicity. You can use Flarum to easily set up a discussion forum for your website. Flarum is developed openly on GitHub.

Since its creation in 2000, phpBB™ has become the most widely used Open Source forum solution. Like its predecessors, phpBB™ 3.2 “Rhea” has an easy to use administration panel and a user friendly installation process, which allows you to have a forum set up in minutes.

Simple Machines Forum — SMF in short — is a free, professional grade software package that allows you to set up your own online community within minutes.

MyBB is the free and open source, intuitive, extensible, and incredibly powerful forum software you've been looking for.With everything from forums to threads, posts to private messages, search to profiles, and reputation to warnings, MyBB features everything you need to run an efficient and captivating community. Through plugins and themes, you can extend MyBB's functionality to build your community exactly as you'd like it.

bbPress is forum software with a twist from the creators of WordPress. Its focused on web standards, ease of use, ease of integration, and speed. bbPress will try to keep things as small and light as possible while still allowing great add-on feature possibilities.

vBulletin (abbreviated as vB) is a commercial Internet forum software produced by Jelsoft Enterprises. It is written in PHP using a MySQL database server.

A compelling community experience. Intuitive. Social. Engaging. Fast. XenForo brings a fresh outlook to forum software.

Invision Power Board (abbreviated IPB, IP.Board or IP Board) is an Internet forum software produced by Invision Power Services, Inc. It is written in PHP and primarily uses MySQL as a database management system, although support for other database engines is available.

FluxBB is a fast, light, user-friendly forum application for your website. FluxBB was designed as a lighter, faster alternative to some of the traditional feature heavy forum applications. It is easy to use and has a proven track record of stability and security making it an ideal choice of forum for your website. FluxBB produces valid XHTML 1.0 Strict pages, supports UTF-8 and is Free to use (GNU GPL)

WoltLab Suite (formerly Burning Board) is an enterprise grade CMS built for communities and forums.

Communicate with the world…

IkoBB is a new open source forum which aim it is to fullfull the wishes and dreams of it's community. New features like emojis support, responsive design, Account usage of GitHub and Facebook and general features for a forum or bulletin board are the core of this bulletin board. IkoBB tries to stay up to date with the newest technology and to improve the handle for every user.

Forum(s) built with JavaScript ( with CoffeeScript ) and alternativeto.net/software/json for the database distributed by the network ZeroNet