What is Simple Machines Forum used for?

Simple Machines Forum is free PHP community forum software for setting up and running online discussion boards on MySQL or PostgreSQL. It is a good fit for hosting a discussion forum for a club or product and running a community without a hosted forum service.

Is Simple Machines Forum open source?

Yes. Simple Machines Forum is open source under a custom licence. Its source code is on GitHub at SimpleMachines/SMF and is written mainly in PHP.

Is Simple Machines Forum free?

Yes. Simple Machines Forum is open source, so the software itself is free to use under the terms of its own licence.

Can I self-host Simple Machines Forum?

Yes. Simple Machines Forum can be self-hosted on your own server or infrastructure.

What is Simple Machines Forum an alternative to?

Simple Machines Forum is an open-source alternative to Vanilla, XenForo, vBulletin and Invision Community. Other open-source alternatives to Vanilla include phpBB, Flarum and Discourse.

Is Simple Machines Forum actively maintained?

Yes. The most recent commit to Simple Machines Forum was on 1 October 2026, and the latest release is v2.1.7, published on 8 March 2026. The project has 749 stars on GitHub.

Simple Machines Forum: open-source alternative to Vanilla

About Simple Machines Forum

Simple Machines Forum, usually shortened to SMF, is free and open-source forum software written in PHP. It is meant for people who want to launch an online community of their own, and the project says an installation can be up and running within minutes using the official release packages.

SMF works with MySQL and PostgreSQL databases. This repository is the development home of the project, with separate branches for the 2.1 and 3.0 release lines. People who work from source rather than a packaged release need Composer 2 or newer to install dependencies, and contributors sign off their commits under the project's licensing terms.

The README states that SMF is licensed under the BSD 3-clause license, while documentation contributions use CC-BY-SA 3 and bundled libraries and image sets keep their own licenses.

Key features

Community forum software written in PHP
Supports MySQL and PostgreSQL databases
Quick setup from official release packages
Separate release branches for 2.1 and 3.0
Composer-based dependency management for source installs

Good fit for

→Hosting a discussion forum for a club or product
→Running a community without a hosted forum service

Built with: PHP; MySQL; PostgreSQL
Tags: forum; community; php; mysql; postgresql; bulletin-board; self-hosted

Simple Machines Forum: questions and answers

What is Simple Machines Forum used for?: Simple Machines Forum is free PHP community forum software for setting up and running online discussion boards on MySQL or PostgreSQL. It is a good fit for hosting a discussion forum for a club or product and running a community without a hosted forum service.
Is Simple Machines Forum open source?: Yes. Simple Machines Forum is open source under a custom licence. Its source code is on GitHub at SimpleMachines/SMF and is written mainly in PHP.
Is Simple Machines Forum free?: Yes. Simple Machines Forum is open source, so the software itself is free to use under the terms of its own licence.
Can I self-host Simple Machines Forum?: Yes. Simple Machines Forum can be self-hosted on your own server or infrastructure.
What is Simple Machines Forum an alternative to?: Simple Machines Forum is an open-source alternative to Vanilla, XenForo, vBulletin and Invision Community. Other open-source alternatives to Vanilla include phpBB, Flarum and Discourse.
Is Simple Machines Forum actively maintained?: Yes. The most recent commit to Simple Machines Forum was on 1 October 2026, and the latest release is v2.1.7, published on 8 March 2026. The project has 749 stars on GitHub.