FlatBB: multilingual out of the box, with a full forum feature set

FlatBB, a new lightweight forum software written in PHP 8.1+, has been released with a full feature set including nested categories, tags, mentions, Markdown support, image uploads, full-text search, and a plugin API. The software requires no build step and ships with multilingual interface packs, targeting small communities that need more than typical lightweight forums.

Most “lightweight” forums cut corners. FlatBB is different: plain PHP 8.1+, no Composer/Docker/build step — but the feature list is what small communities actually need. Interface packs ship in the box: Also: Discussion: nested categories one level + per-group permissions, tags, topics/replies, quotes, @mentions, Markdown + live preview, drag/paste image upload, likes, bookmarks, unread tracking, notifications. Discovery: full-text search SQLite FTS5 / MySQL FULLTEXT , Latest / Top / Unread, clean URLs, RSS, sitemap, profiles & avatars. UX: Discourse/Flarum-style three-column layout that collapses on phones, dark mode, one-click upgrades. Admin: settings, categories, tags, users, groups, layout blocks, plugins, scheduled jobs, tools. Need more? The marketplace and AI-friendly plugin API cover SEO, social login Google/GitHub/X , Q&A, levels, verified badges, Guard/2FA, drafts, and more. Plugin docs for assistants: https://www.flatbb.com/dev/plugins.md https://www.flatbb.com/dev/plugins.md MIT licensed. If you try it, tell us where it breaks — the support forum runs on FlatBB itself.