Vanilla

Vanilla is open source forum software for building community discussions that you can customize to fit the group using them. It has powered tens of thousands of community forums, and is built so designers and developers can craft an environment tailored to a community's particular needs.

Theming flexibility is a core focus, letting you brand the forum freely rather than fit a fixed template. Integration is handled through single sign-on and embedding, so the forum can live inside an existing site and share its accounts. Community management tooling and a curated set of features, extendable with plugins, round out day-to-day moderation.

Vanilla is free software under GPL-2.0-only, maintained by Vanilla Forums Inc. You can self-host it, using the Docker-based local setup, or run it on the company's cloud hosting with professional support and migration services.