Trello's board model on your own server: Planka is an open-source Kanban project management tool. Boards organize into projects with lists, cards, labels, due dates, checklists, file attachments, and per-card stopwatch time tracking, all managed through drag-and-drop. Updates propagate over WebSockets, so a teammate moving a card or adding a comment appears instantly for everyone without a refresh - a genuine differentiator among self-hosted boards. Card descriptions use a full Markdown editor, custom fields adapt cards to your workflow, and views switch between Kanban, grid, and list layouts. Authentication supports OpenID Connect single sign-on with Google, Azure AD, Okta, or any OIDC provider - a feature Trello reserves for enterprise plans - and notifications reach 100+ channels including Slack, Discord, Telegram, and SMTP via Apprise. A REST API with 50+ webhook events supports custom integrations, and one-click board import eases migration. Built with React and Node.js on PostgreSQL, translated into 35+ languages, deployed via Docker.