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.

An Airtable-style spreadsheet interface directly on PostgreSQL: Teable is an open-source no-code database where every table is a real Postgres table. Unlike tools that store records in a metadata abstraction layer, every Teable table is a real Postgres table with standard column types, so filtering, sorting, and grouping run at database speed, million-row tables answer complex filters in roughly 200 milliseconds without index tuning, and any PostgreSQL-compatible tool - psql, BI dashboards, ETL pipelines - can query the same data directly. The interface offers Grid, Kanban, Gallery, Calendar, and Form views as non-destructive overlays with their own filters and hidden fields, plus 20+ field types, formulas, comments, attachments, batch editing, undo/redo, and edit history. Collaboration is real-time with live cursors and instant sync across views, backed by Redis, and a REST API is auto-generated per table, largely compatible with Airtable API clients - alongside native SQL access for BI tools, analytics pipelines, and your own applications to JOIN and query directly, with no exports, API rate limits, or sync jobs. Global search spans all records, chart plugins handle quick visualization, and CSV and Excel import/export cover migrations. Where Airtable caps paid plans at 100K-500K rows and charges roughly $20 per user per month, a self-hosted Teable instance has neither limit: the Postgres database itself is the export if you ever leave. Built in TypeScript with NestJS, deployed via Docker with PostgreSQL and Redis, and licensed AGPL-3.0.

From the Mattermost team comes Focalboard, an open-source, MIT-licensed project board tool - a self-hosted alternative to Trello, Asana, and Notion databases, written in Go with a React frontend. Every board renders the same card data four ways: Kanban with drag-and-drop columns, a spreadsheet-style table, an image-forward gallery, and a calendar. Cards carry unlimited custom properties - dates, dropdowns, checkboxes, people, URLs - and boards can be grouped, filtered, and sorted by any property combination, with unlimited saved filtered views for quick access. Built-in templates cover the common workflows (meeting agendas, content calendars, project tasks, roadmaps, sprint planning), or you can build fully custom boards from scratch. Collaboration is real: card comments with @mentions, per-board permissions for teams or individuals, file attachments stored on your own infrastructure, and archiving with backup snapshots. Migration tooling imports existing boards from Trello (JSON export), Asana, and Notion, so switching does not mean starting over. It ships in 20+ languages and runs as a lightweight multi-user personal server. Worth knowing before deploying: Mattermost has shifted primary development to the integrated Mattermost Boards plugin, so the standalone edition is community-maintained - stable and functional, but evolving slowly. For teams wanting a free, private Trello without per-user fees, it remains a solid pick.

Nearly two decades running engineering organizations: Redmine is the veteran open-source project management and issue tracker, a Ruby on Rails application (GPLv2) still in active development. Its core strength is configurability: define your own trackers (bug, feature, task, or anything else), issue statuses, and role-based workflows that control exactly which transitions each role may perform, then extend records with custom fields of every type. Issues support subtasks, relations (blocks, precedes, duplicates), watchers, categories, and full journaled history, with saved custom queries and cross-project filtering for slicing the backlog any way you need. Around the tracker sit Gantt charts and calendars, a roadmap driven by versions, per-project wikis, forums, news, and document repositories, plus time tracking with estimated versus spent hours and activity-based reporting. Multi-project support runs deep - subprojects, per-project modules, and granular role-based permissions - and repository integration (Git, Subversion, Mercurial) links commits to issues automatically. Email notifications, inbound email-to-issue creation, LDAP authentication, a REST API, and a large plugin and theme ecosystem round it out. Recent 6.x releases brought substantial query and rendering optimizations. Self-hosting keeps your entire project history in your own database, free of per-seat licensing.

"As simple as Trello but as feature-rich as Jira" is how the Leantime team frames its goals-focused project management system for non-project managers - built from the ground up with ADHD, autism, and dyslexia in mind, with behavioral science shaping customizable dashboards, time blocking, low-cognitive-load prioritization, and Kanban, list, table, Gantt, and calendar views so each person works the way their brain does. The PHP application (AGPL, Laravel Blade frontend) connects strategy to execution: tasks with unlimited subtasks and dependencies roll up into milestones on a timeline, sprints and retrospectives handle iteration, and strategy-level blueprint boards - Lean Canvas, SWOT, risk analysis, goal and metric tracking - keep the "why" attached to the work. Knowledge lives alongside: wikis and docs, idea boards, comments on everything, file storage on S3 or local disk, even screen and webcam recording. Time tracking with timesheets supports estimation and client billing. Admin features are serious for an OSS tool: per-project permissions, two-factor auth, LDAP and OIDC single sign-on, Slack, Mattermost, and Discord integrations, a plugin system, and an expanding API that now powers a mobile app. Recent releases added multi-collaborator task assignment and low-vision accessibility improvements. Available in 20+ languages.

What Trello fans wanted Trello to stay: Kan (kan.bn) is a minimalist, frills-free kanban board capturing the original vision before the enterprise pivots - and then adds the things 2025 actually demands. The core is exactly right: drag-and-drop cards across lists, labels and filters to find work fast, comments for discussion on cards, checklists, a detailed activity log tracking every change, and reusable board templates. Workspaces gather your team with member invites and role management, and board visibility controls decide who can view or edit each board. Migration is first-class: a built-in Trello importer brings existing boards over, so switching costs an afternoon, not a quarter. The standout differentiator is the bundled Model Context Protocol server exposing 46 tools across workspaces, boards, lists, cards, comments, checklists, labels, and members - meaning Claude Desktop, Cursor, Copilot, or any MCP client can read and manage your boards in natural language: "move everything assigned to me into Done" becomes a sentence, not a click marathon. The stack is modern TypeScript - Next.js, tRPC, Drizzle ORM over PostgreSQL, Better Auth (credentials or OAuth), Tailwind - with optional SMTP email and S3 file storage. Unlimited boards, lists, and cards; AGPL-licensed.