MyBB

MyBB is a free, open‑source forum platform written in PHP that can be self‑hosted without a subscription. It provides a web‑based interface for creating and managing online communities, supporting typical discussion features such as threads, private messaging, user profiles, and moderation tools. The software includes a built‑in template and theme editor, allowing administrators to customize the appearance and layout of their forums.

The project is extensible through a plugin system and a collection of community‑contributed themes, enabling additional functionality and visual designs without modifying core code. Multilingual support is provided via community‑maintained translations for more than thirty languages, and the interface is designed for ease of use by both users and administrators.

MyBB is maintained by a volunteer community and distributed under the LGPL‑3.0 license. Documentation, support forums, and contribution guidelines are available online, and the codebase is hosted publicly with separate branches for the stable 1.6 series and the actively fixed 1.8 series.