With over 75,000 GitHub stars and native apps across macOS, Windows, Linux, iOS, and Android, AppFlowy is the most widely adopted open-source alternative to Notion — delivering the same block-based workspace model with full data sovereignty. The Flutter frontend renders natively on every platform while a Rust backend powered by Actix-web and Tokio handles CRDT-based real-time collaboration, ensuring sub-second sync across devices with conflict-free concurrent editing. Relational databases support grid, board, kanban, calendar, and gallery views over the same dataset, with two-way relations, rollups, advanced filters, sorts, and formula calculations that cover the majority of Notion's database workflows. The block editor supports 40+ content types including nested pages, toggles, callouts, code blocks with syntax highlighting, embeds, and slash-command insertion. AI integration connects to OpenAI, Anthropic, or local models via Ollama for writing assistance, summarization, and translation — all without sending data off-premises when using on-prem LLMs. Team spaces with workspace-level and per-page permissions, OAuth and SSO authentication through GoTrue, and S3-compatible object storage via MinIO provide enterprise-grade access control and file management. The self-hosted stack deploys through Docker Compose with PostgreSQL for metadata, Redis for caching and pub/sub, and a dedicated background worker for imports and email notifications. Offline-first architecture ensures the desktop app functions without connectivity, syncing changes when the connection resumes. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.

With nearly 10,000 GitHub stars and over a decade of development since 2013, Invoice Ninja is the most complete source-available invoicing platform for freelancers and small businesses — combining professional invoicing, online payments, expense tracking, and project management in a single self-hosted application. The Laravel API backend powers a React web portal and Flutter native applications for Windows, macOS, Linux, iOS, and Android, delivering a consistent experience across every device. Create professional invoices and quotes with real-time PDF preview, product libraries, custom templates, and automatic tax calculations. Clients receive branded emails and access their dedicated portal at your custom domain to view documents, approve quotes with e-signatures, and pay with one click via Stripe, PayPal, Square, GoCardless, Authorize.net, Braintree, or Mollie. Recurring invoices with auto-billing charge saved payment methods on schedule — weekly, monthly, or annually — with automatic reminders and late fee calculations. The built-in project management suite includes Kanban boards for task organization, billable time tracking with start/stop timers, and vendor expense management with receipt attachments. Bank account synchronization via Yodlee or GoCardless automatically imports transactions for reconciliation. E-invoicing with PEPPOL network integration supports electronic invoicing standards for European and government compliance. Reports cover invoices, expenses, profit and loss, tax summaries, and aged receivables. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Elastic License v2.

Scrumboy is a Kanban and sprint management tool that ships as a single Go binary backed by SQLite, deploys in under ten seconds via Docker, and uniquely integrates with AI coding agents through a standards-compliant MCP JSON-RPC endpoint. The dual-mode architecture supports Full mode with bootstrapped authentication, TOTP two-factor auth, OIDC/SSO integration through Keycloak, Authentik, Auth0, or Entra ID, role-based access control across Owner, Admin, User system tiers plus per-project Maintainer, Contributor, and Viewer roles, and Anonymous mode that generates instant shareable boards accessible via unique URLs with zero signup requirement. Custom workflows allow user-defined lane configurations per project including designated "Done" lanes, while sprints with configurable one or two-week cycles include board-level sprint filtering and the ability to disable and re-enable sprint tracking without losing history. Real-time Server-Sent Events power instant multi-user board updates, and outbound webhooks deliver JSON payloads to registered URLs when domain events fire with HMAC signature verification. The MCP endpoint at /mcp/rpc enables native integration with Cursor, Claude Code, and other AI agents through OAuth 2.1 with PKCE authorization, while API access tokens support CLI automation and CI/CD pipelines. Additional capabilities include VoiceFlow voice commands, per-project sticky-note walls, Markdown and Mermaid diagram support in task notes, append-only audit trails, VAPID Web Push notifications, SMTP password reset, Trello import, JSON backup with merge/replace/copy strategies, and 22-language internationalization. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL v3.0 licensed.

With over 15,100 GitHub stars and seven years of battle-tested production use, OneDev replaces entire DevOps toolchains — GitLab, Jenkins, Jira, Artifactory — with a single Java application that runs comfortably on a 1-core 2GB server for medium-sized projects. The platform unifies Git hosting with ANTLR-powered language-aware code search and symbol navigation, pull request workflows with configurable branch protection rules and required reviewers, and customizable issue tracking with scripted state transitions that automatically advance issues when code is committed, builds pass, or deployments complete. The GUI-based CI/CD editor creates pipelines without writing YAML, supporting typed parameters, matrix builds, job templates, cache management, and artifact publishing in a single visual interface. Jobs execute via Docker containers, bare metal shell, Kubernetes pods, or distributed agent pools, with web terminal access for live debugging and the ability to pause running jobs for inspection. Built-in package registries handle Docker images, npm packages, Maven artifacts, NuGet libraries, PyPI wheels, and RubyGems without external infrastructure. AI users can be assigned to issues and pull requests to autonomously implement features, review code, fix CI/CD failures, and resolve merge conflicts. The automated Kanban board supports rule-based card movement, time tracking, timesheets, and service desk ticket creation via email. Cluster deployment enables project replication across servers for high availability and horizontal distribution for scalability. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

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.

Reaching 45,000 GitHub stars within seven months of launch, Multica is the fastest-growing open-source platform for managing AI coding agents as first-class teammates — assign an issue to Claude Code, Codex, Cursor, Copilot, Kimi, or any of 21 supported agent CLIs and it picks up the work, comments progress in real time via WebSocket, raises blockers, and hands the result back for human review before anything merges. The Go backend (Chi router, sqlc-generated type-safe queries, gorilla/websocket) connects to PostgreSQL 17 with pgvector for semantic search across workspace history, while the Next.js 16 App Router frontend delivers workspace dashboards showing per-agent token spend, execution time, daily cost charts, and runtime status across unlimited connected machines. Agent Skills provide reusable methods, reference material, and supporting files that compound across runs — a persistent knowledge layer that makes each subsequent task faster and more accurate. Squads let a leader agent select the right specialist for subtasks, creating multi-agent workflows without manual orchestration. Review gates ensure no AI-generated code ships to main without explicit human approval. Self-host via Docker Compose or Kubernetes with full Git integration across GitHub, GitLab, Gitea, and Forgejo including self-hosted instances. The CLI and REST API make every surface scriptable, and Autopilot automations trigger agent runs from events. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed with additional conditions.

With over 57,000 GitHub stars and deployment across thousands of organizations worldwide, Gitea is the most popular self-hosted Git service, delivering a complete software development platform in a single Go binary that runs on as little as 512MB of RAM. The platform provides full repository management with pull requests featuring inline code review, branch protection rules, merge strategies including squash, rebase, and merge commit, and automated status checks through Gitea Actions. The built-in CI/CD system uses the same YAML workflow syntax as GitHub Actions and can directly reuse over 20,000 existing Actions plugins, allowing teams to migrate from GitHub with minimal pipeline rewrites using the open-source act_runner executor. The integrated package registry supports over 20 formats including npm, PyPI, Maven, NuGet, Cargo, Helm, Composer, Conda, RubyGems, Pub, and an OCI-compatible Container registry for Docker images with no additional configuration required. Project management features include issue tracking with labels, milestones, dependencies, and time tracking, alongside kanban project boards for visual workflow management. Gitea supports LFS for large file storage, built-in wiki pages per repository, webhook integrations with Slack, Discord, Telegram, Microsoft Teams, and custom HTTP endpoints, and OAuth2 authentication with LDAP, SAML, and PAM backend support. Repository mirroring enables bidirectional synchronization with GitHub, GitLab, and Bitbucket, while the comprehensive REST and GraphQL APIs power external integrations and the official tea CLI tool. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Winner of the 2015 Most Valued Agile Tool award and cited as a top project management platform by Opensource.com with over 2,100 GitHub stars on the Docker deployment repository alone, Taiga has served an estimated 20 million users worldwide with over 2 million Docker pulls since its creation in 2014 by Kaleidos. The platform delivers a complete agile project management experience through Scrum boards with backlog prioritization, sprint planning, story point estimation configurable per role, burndown charts at both project and sprint levels, and velocity tracking with a project doom-line indicator. Kanban boards offer customizable workflow columns with swimlanes, WIP limits, zoom controls, and the ability to switch between Scrum and Kanban at any point without losing data. The issue tracker supports custom types, priorities, and severities with the ability to promote issues directly to user stories. Team collaboration features include threaded comments, file attachments, email notifications, mentions, a built-in wiki for project documentation, and a team performance dashboard with the Iocane health metric for tracking team sustainability. The platform integrates with GitHub, GitLab, and Bitbucket for version control linking, provides importers for migrating from Trello and Jira, and exposes a REST API for custom integrations. Available in over 20 languages with custom fields, tags, roles, and permissions. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MPL-2.0 licensed.

With over 37,800 GitHub stars and active development since its first release in 2008, ERPNext is the most-starred open-source ERP system — delivering accounting, inventory management, manufacturing, CRM, project tracking, asset management, HR, and point-of-sale capabilities through a unified web interface built on the Frappe Framework's metadata-driven architecture. The accounting module handles multi-company consolidation, multi-currency transactions, tax templates for GST and VAT, bank reconciliation, and automated journal entries with real-time profit and loss, balance sheet, and cash flow reporting. Manufacturing covers production planning with multi-level bill of materials, work order scheduling, capacity planning, subcontracting, and quality inspection at each production stage. Inventory tracks stock across multiple warehouses with batch and serial number tracing, automatic reorder levels, landed cost calculations, and perpetual inventory valuation using FIFO or moving average methods. The CRM module manages leads, opportunities, and customer communication with email integration, while project management tracks tasks, timesheets, and Gantt-based scheduling with budget controls. Custom applications extend functionality through the Frappe ecosystem without forking the core codebase, and the REST API enables integration with payment gateways, shipping providers, and third-party services. Deployable via Docker Compose or the bench CLI tool with MariaDB and Redis. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed.

Kandev provides a command center for orchestrating AI coding agents across parallel workstreams. The Go backend paired with a Next.js frontend delivers kanban boards with drag-and-drop columns, pipeline workflow definitions with per-step agent handoffs, and an IDE-like review workspace combining file editor, file tree, terminal, browser preview, and unified git diffs. Multi-provider support connects Claude Code, GitHub Copilot, Codex, Qoder, Grok, and custom agents through configurable profiles with per-agent prompts, runtimes, and review gates. Tasks execute in isolated git worktrees with multi-repository support, letting agents work on separate branches simultaneously while changes surface in a consolidated review interface. Native integrations with GitHub, GitLab, Jira, Linear, Sentry, and Slack pull external issues into the kanban and link tasks to pull requests. Kandev exposes streamable HTTP and SSE MCP endpoints, enabling external clients — Cursor, Claude Desktop, Augment — to create tasks and read workspace context programmatically. Workflow definitions export as portable YAML for sharing across installations. Agentic workflows chain multi-step pipelines mixing different models per step — Opus for architecture, Sonnet for implementation, with human review gates between stages. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.

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.

From a freelancer logging billable hours to companies with hundreds of users, Kimai scales professional-grade open-source time tracking - a Symfony/PHP application without the per-seat pricing of Harvest or Toggl. Tracking is flexible by design: run multiple concurrent timers, use punch-in/punch-out mode, or enter times manually, organized by customer, project, and activity with tags, and priced by user-, customer-, or project-specific rates. The billing pipeline is where Kimai earns "professional grade": generate invoices directly from timesheet data with configurable templates (DOCX, ODS, XLSX, PDF), entry grouping, and invoice-number generators, while an export flag locks billed records against editing and excludes them from future invoices - the audit-safety detail spreadsheet workflows never get right. E-invoicing supports EN 16931, XRechnung 3.0, and Zugferd/Factur-X. Enterprise controls come standard: SAML and LDAP login against Google Workspace, Azure AD, or Authentik, TOTP two-factor auth, customizable role permissions, and teams that scope customers and projects to departments. Money and time budgets alert before overruns, advanced reporting slices recorded time by any dimension, and an extensive JSON API plus a plugin marketplace (expenses, approvals, and more) integrate it with existing infrastructure. Over 30 translations, multi-timezone, AGPL-licensed.

Macro merges email, team chat, collaborative documents, task management, CRM, and video calls into one keyboard-driven application where AI agents operate across the entire workspace with shared team memory, replacing the Slack plus Notion plus Linear plus Superhuman plus HubSpot stack with a single deployment. The email module provides a multi-account unified inbox with keyboard shortcuts, shared team inboxes, and Gmail integration. Team messaging offers channels and direct messages designed for technical discussions with threaded conversations. The task system draws from Linear with board and list views tightly integrated with channels, email threads, and AI agents. Real-time collaborative documents use CRDT synchronization via Loro for conflict-free editing with Markdown-native formatting and @mention linking. A 2D canvas board embeds @links to tasks, files, and emails for visual project planning. AI agents access unified team-level memory spanning all workspace modules, taking autonomous actions across email, chat, tasks, and documents through MCP-compatible tool interfaces. Video calls include recording, transcription, and automatic logging to team memory. The CRM module tracks customers and contacts with custom properties, email synchronization, and data enrichment. Eighty-plus Rust microservices on the Axum framework handle backend operations while a SolidJS static SPA delivers the frontend with instant search and real-time collaboration. Docker Compose deployment provisions the complete service stack with PostgreSQL, Redis, OpenSearch, and FusionAuth authentication. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.

Replacing HubSpot, Zendesk, Intercom, and Linear with a single self-hosted platform, erxes delivers an Experience Operating System trusted by over 4,000 GitHub stars and built on a modern Nx-powered monorepo architecture. The core ships with six foundational modules — My Inbox for omnichannel conversations across email, web chat, voice, and Discord; Contacts for unified customer profiles; Products for catalog management; Segments for behavioral targeting; Automation for visual workflow builders; and Documents for template generation. Beyond the core, a plugin marketplace activates Frontline for ticket management and omnichannel support queues, Sales for deal pipelines and lead scoring, Operations for project boards with cycle management, Content for headless CMS and knowledge bases, and Team for employee directories, time clocks, and internal chat. The technical stack combines GraphQL Federation with Apollo Server v4 and tRPC v11 microservices on Node.js, React 18 micro-frontends via Rspack Module Federation with TailwindCSS 4, MongoDB with Mongoose for persistence, Redis for caching, BullMQ for job queues, and Elasticsearch for full-text search. Deployment supports Docker Compose orchestration with automatic service discovery across all plugin containers. The Global Profile architecture enables agencies to manage multiple client brands under a single login with separated data stores. iOS and Android SDKs embed the messenger widget directly into mobile applications. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPLv3 licensed.

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.

With nearly 8,000 GitHub stars since its December 2024 launch, Kaneo has rapidly gained traction as the minimalist alternative to bloated project management platforms like Jira and Linear. Built on TypeScript with React and Hono, the interface strips away complexity to focus on execution — plan in list view, track in kanban board, and schedule on interactive Gantt chart timelines where dragging bar handles adjusts start and due dates with optimistic UI updates. Native GitHub integration synchronizes issues bidirectionally, links pull requests to tasks, and keeps product planning aligned with development execution without context switching. The built-in Model Context Protocol server at /api/mcp enables AI tools like Claude and Cursor to manage tasks, projects, and labels directly, while the official @kaneo/mcp npm package provides stdio access for local MCP clients. Authentication supports password, magic link, GitHub OAuth, and Google sign-in with organization-level access management. Rich text editing for task descriptions and comments, label-based initiative grouping, priority levels, assignee management, and due date tracking provide focused planning without ceremony. Deploy with the drim CLI for automatic HTTPS and database setup, Docker Compose for custom configurations, or Helm charts for Kubernetes clusters — all requiring just 2GB RAM and PostgreSQL. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

A personal to-do list that scales to team project management: Vikunja is an open-source task manager that grows with the work. Every project can be viewed four ways - classic list, drag-and-drop Kanban board, Gantt chart for timeline planning, and a spreadsheet-style table - so a project manager watches the Gantt while developers work the board, on the same data. Tasks carry the full attribute set: labels, priorities, due dates and reminders, recurring schedules, subtasks and task relations, file attachments, assignees, and comments, and Quick Add Magic parses natural-language input like dates and labels typed inline. Projects share with team members or via links, and saved filters slice tasks across projects. Built-in CalDAV support (VTODO) syncs tasks bidirectionally with clients like Thunderbird, DAVx5, and iOS Reminders, and one-click importers migrate from Todoist, Trello, and Microsoft To-Do. Nothing is metered - unlimited projects, tasks, filters, and attachments. A single Go binary with a Vue frontend runs against SQLite, MySQL, or PostgreSQL, exposes a full REST API, and works as an installable PWA on mobile. AGPLv3-licensed.

The most-starred open-source project management platform on GitHub with over 55,000 stars, Plane delivers what Jira, Linear, Monday, and ClickUp charge thousands per year for — issue tracking, sprint planning, documentation, and AI-powered workflows in one unified workspace that you own and control entirely. Work items feature a rich text editor with file uploads, sub-properties, custom states, priorities, labels, assignees, and cross-referencing, organized across five customizable layout views (list, board, table, spreadsheet, Gantt) with Command-K navigation for instant access to anything. Time-boxed Cycles provide sprint planning with automatic burn-down charts, velocity tracking, and scope change detection, while Modules break complex projects into manageable deliverables with progress aggregation. Built-in Pages combine AI-powered documentation with rich formatting, image embedding, and one-click conversion of notes into actionable work items. The AI layer reads across every project, cycle, document, and thread in the workspace — agents take real assignments, triage incoming requests, assign owners, track blockers, and ship status updates automatically. Native integrations connect GitHub, GitLab, Slack, Sentry, Figma, and 50+ tools with bidirectional issue sync and PR tracking, while import pipelines migrate entire workspaces from Jira, Linear, Asana, ClickUp, or Monday in minutes. The REST API with OAuth 2.0, HMAC-signed webhooks, typed SDKs in Node.js and Python, and a native MCP server enable custom automations. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.