Neko
With over 21,000 GitHub stars and six years of steady development through version 3.1.0, Neko transforms any Docker container into a fully interactive browser or desktop environment streamed to web browsers via WebRTC with sub-300-millisecond glass-to-glass latency. The Go backend captures X server display frames using the Pion WebRTC library while the Vue.js frontend renders the remote session with native audio synchronization, delivering a significantly smoother experience than Apache Guacamole or noVNC which rely on image-over-WebSocket approaches. Multiple users simultaneously view and collaboratively control the same session with real-time input synchronization and host-managed control passing between participants. Pre-built Docker images cover Firefox, Chromium, Google Chrome, Tor Browser, Brave, Vivaldi, and Microsoft Edge alongside full desktop environments including XFCE and KDE for running any Linux application. Neko Rooms provides multi-tenant deployment with a REST API for programmatic room provisioning, while Neko Apps extends the platform with additional containerized applications beyond browsers. Sessions persist on the server independently of client connections — close your laptop, reconnect from your phone, and resume exactly where you left off. Optional VPN and Tor integration routes traffic through encrypted tunnels for privacy-sensitive browsing. RTMP broadcasting streams sessions to external platforms. The embeddable client supports iframe integration for custom portals and applications. 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.
Weblate
Over 2,500 open-source projects and companies in more than 165 countries localize with Weblate - the libre continuous localization platform and the standard self-hosted answer to Crowdin and Lokalise. Its defining trait is that translations live in the same version control as your code: Weblate talks directly to Git and Mercurial, pulls new source strings automatically via webhooks, and pushes finished translations back either as direct commits or as pull/merge requests on GitHub, GitLab, Gitea, Bitbucket, Azure DevOps, Gerrit, or Pagure. Every translator is properly credited in the commit history. For translators, it is a full computer-aided translation tool: translation memory, glossaries, customizable quality checks that catch placeholder and formatting mistakes, propagation of identical strings across components, and automatic suggestions from machine translation services - DeepL, Amazon Translate, LibreTranslate, and others, with per-service priorities and support for custom Python engines. It handles the format zoo (gettext PO, JSON, YAML, Android XML, iOS strings, and dozens more) and supports crowdsourced workflows with granular access control, workspaces, two-factor authentication, and reviewer approval steps. A REST API, CLI client, and add-on system automate everything else. Built on Python/Django, GPL-licensed, with no per-string or per-seat pricing when self-hosted.
Vaultwarden
The Bitwarden server, reimplemented in Rust: Vaultwarden (formerly bitwarden_rs) is the unofficial lightweight edition. It speaks the same wire protocol as the official server, so every official Bitwarden client - browser extensions, iOS, Android, desktop, and the bw CLI - connects without modification, while the server itself runs as a single container against SQLite (or MySQL/MariaDB/PostgreSQL) instead of the official multi-container stack that wants gigabytes of RAM. Features Bitwarden gates behind paid tiers ship free: organizations with collections, groups, member roles, and policies; TOTP code storage; file attachments; Bitwarden Send; Emergency Access; event logs; and admin password reset. Two-factor options cover authenticator apps, email, FIDO2 WebAuthn, YubiKey, and Duo, and OIDC-based SSO landed natively in v1.35.0. Zero-knowledge encryption is unchanged - vault data is encrypted client-side and the master password never reaches the server. Attachments and Sends store on local disk or S3-compatible backends, an admin panel manages users and server settings, and backup is copying one data directory. Suited to individuals and teams up to roughly 50 users.
Haven
Haven gives your community a private chat server with voice calls, screen sharing, and end-to-end encrypted direct messages where friends join via invite link in their browser without installing apps or creating third-party accounts. Real-time messaging supports image uploads via paste and drag-drop, emoji reactions, replies, threads, typing indicators, @mentions with autocomplete, and inline GIF search through Tenor or GIPHY. Peer-to-peer WebRTC voice chat includes per-user volume sliders, mute and deafen controls, talking indicators, and screen sharing with picture-in-picture mode. Direct messages use ECDH P-256 key exchange with AES-256-GCM symmetric encryption where private keys never leave the browser, ensuring not even the server operator can read them. Twenty-plus visual themes with stackable effects including CRT scanlines, Matrix Rain, Cyberpunk Text Scramble, Snowfall, and Campfire Embers let users personalize the experience with configurable intensity sliders. Rich Presence integration shows what members are playing or listening to via Last.fm, Steam, and Spotify. A built-in bot API supports webhooks and custom slash commands, while Discord history import preserves channels, threads, forums, reactions, pins, and avatars. The Node.js server deploys via Docker Compose or a single batch file that auto-handles dependencies, SSL certificates, and configuration. 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.
Suite Docs
An open-source alternative to Notion and Google Docs developed jointly by France's DINUM and Germany's ZenDiS that prioritizes data sovereignty, real-time collaboration, and structured knowledge management. The Yjs-powered CRDT engine provides live cursors, presence indicators, and inline comments enabling teams to edit simultaneously without conflicts, while BlockNote.js renders a clean block-based editing experience with rich text formatting, Markdown shortcuts, and drag-and-drop content organization. Hierarchical sub-documents create wiki-style knowledge bases where documentation nests naturally into navigable structures, and a dedicated slide mode transforms any document into a presentation without separate tooling. The document API separates content from metadata with distinct endpoints for formatted content, raw content streams, and document properties. Optional AI integration connects to configurable language models for writing assistance, summarization, and content generation directly within the editor. Access control supports granular permissions per document with team sharing, public links, and invitation flows. DOCX import brings existing documents into the platform while maintaining formatting fidelity. The Django backend serves a REST API with PostgreSQL storage, Redis caching, and S3-compatible media handling. Deploy via Docker Compose, Kubernetes with the official Helm chart, Nix, or YunoHost on your own infrastructure. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.
Multica
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.
Colanode
With nearly 5,000 GitHub stars and a Hacker News launch that garnered 147 points, Colanode delivers the first genuinely local-first alternative to both Slack and Notion in a single self-hosted workspace — writing every operation to a client-side SQLite database before syncing to your server, so teams work at full speed offline, on planes, or through intermittent connections without ever losing a draft. The real-time chat system provides channels and direct messages with instant delivery via WebSocket, while the rich text editor offers Notion-style block-based pages for documents, wikis, meeting notes, and knowledge bases with headings, code blocks, embeds, and nested hierarchies. Customizable databases organize structured data with custom fields and three dynamic views — table for spreadsheet-style browsing, kanban for visual workflow boards, and calendar for time-based planning. Conflict-free Replicated Data Types powered by Yjs handle concurrent editing across pages and database records: multiple users modify the same document simultaneously and the system merges changes automatically without manual conflict resolution. File management supports upload, sharing, and organization within workspaces using pluggable storage backends including local filesystem, S3-compatible services, Google Cloud Storage, and Azure Blob Storage with TUS resumable uploads for large files. The server runs Fastify with Zod validation on Node.js 20+, persists to PostgreSQL with pgvector extension, uses Redis for event broadcasting, and deploys via a single Docker image. 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.
Grist
With over 11,200 GitHub stars and adoption by France's sovereign digital workspace LaSuite serving 20,000+ government users, Grist is the relational spreadsheet that ends the false choice between fragile Excel files and expensive custom database development — storing all data in portable SQLite files while providing true relational structure where VLOOKUPs become actual linked records that update instantly across entire documents. Python-powered formulas replace complex Excel syntax with clear, readable logic using the full Python standard library, while familiar Excel functions remain available for users who prefer them. Granular access rules control permissions at row, column, table, and cell levels — not just entire sheets — enabling multi-department documents where each team sees only their authorized data. The flexible layout system combines spreadsheets, card views, charts, calendars, and custom widgets on configurable dashboard pages that transform raw data into operational interfaces. Real-time collaboration lets multiple users edit simultaneously with automatic snapshot history capturing every change for full audit trails and point-in-time recovery. AI formula assistance connects to OpenAI, Llama, or any OpenAI-compatible endpoint via OpenRouter to generate formulas from natural language descriptions. The REST API and webhooks enable integration with n8n, Zapier, and custom automation, while incremental imports keep external data sources synchronized. Deployable via Docker with OIDC, SAML, and SCIM authentication support. 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.
Focalboard
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.
Taiga
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.
Rallly
What Doodle did before ads and paywalls took over: Rallly (three L's) lets you propose a few dates, share a link, and watch an availability grid fill in - no email threads, no forced accounts, no "$6.95/month to remove ads." The availability grid makes the winning slot obvious at a glance, comments on each poll keep the "I can do Tuesday if we start late" discussion attached to the decision instead of buried in chat, and email notifications fire as votes and comments arrive. When consensus lands, finalize the winning option and everyone gets notified. The stack is modern TypeScript - Next.js, tRPC, Prisma over PostgreSQL, Tailwind - with a clean, genuinely mobile-friendly UI, dark mode, and community translations in 10+ languages. Self-hosting means unlimited polls and unlimited participants with meeting data on your server rather than a scheduling SaaS. It pairs naturally with Cal.com: Rallly answers "which time works for everyone?", Cal.com handles "book a slot on my calendar." AGPL-licensed.
Docmost
Confluence and Notion both want your team's documentation in their cloud; Docmost, an open-source collaborative wiki platform, keeps it on your server. The centerpiece is a Notion-style block editor with CRDT-based real-time collaboration: multiple people edit the same page simultaneously and changes merge without conflicts or overwrites. Content lives in spaces - per team, project, or department - with nested page trees, role-based permissions, groups, inline comments, page history with restore, and full-text search across everything. The editor covers tables, code blocks, callouts, KaTeX math, and file attachments, and diagramming is built in rather than bolted on: Mermaid, Draw.io, and Excalidraw all render inside pages, alongside embeds for Airtable, Loom, Miro, and more. Migration paths include Notion, Markdown, HTML, and ZIP archive imports (Confluence, PDF, and DOCX importers ship in the Enterprise edition, along with SSO via SAML/OIDC/LDAP and MFA). The stack is TypeScript with PostgreSQL and Redis, deploys via Docker Compose, runs in air-gapped environments with no external dependencies, and is translated into 10+ languages. The AGPL-3.0 community edition carries no per-seat fees; the project has passed 20,000 GitHub stars since its 2024 launch.
Bookstack
Most wikis die of flat page-and-tag sprawl; BookStack's defining decision is enforced structure - an MIT-licensed PHP/Laravel platform (over MySQL) where content lives in a hierarchy of shelves, books, chapters, and pages, the way a physical library works. A shelf maps to a department, a book to "Engineering Runbooks," a chapter to "Database Procedures," a page to the actual document. That opinionation removes the "where does this go?" friction and keeps knowledge bases tidy as they grow. Editing works both ways: a clean WYSIWYG editor for most users, a Markdown editor with live preview for those who prefer it - switchable per page. Full-text search spans all books or scopes to one, with direct links to individual paragraphs, and include tags let you embed one page's content inside another so shared blocks update everywhere at once. Every edit creates a diffable, revertible revision. Page templates standardize recurring formats, tags add cross-cutting categorization, and built-in diagrams.net integration draws architecture diagrams in place. Authentication covers email/password plus OIDC, SAML2, LDAP, and social login; a full role and permission system locks content down per shelf, book, or page. Pages and books export to PDF, HTML, plain text, and Markdown, a REST API automates content, and the whole thing runs happily on the cheapest VPS you can find.
Answer
Run a Stack Overflow of your own: Apache Answer brings the question-and-answer format in-house, maintained under the Apache Software Foundation with an Apache-2.0 license. You use it to run a community forum, product help center, or internal knowledge base where content lives as questions and answers rather than wiki pages. It ships the mechanics that make that format work: voting, accepted answers, a reputation system with privilege levels, tagging, full-text search with filters, revision history on every edit, and admin/moderator/user roles. Content is written in Markdown with real-time preview and code syntax highlighting. A plugin system covers OAuth login (Google, GitHub), S3 storage, external search backends like Algolia, and Akismet anti-spam, and a REST API exposes platform data for integration. The backend is Go, the frontend React, and it runs against SQLite, MySQL, or PostgreSQL. Self-hosting replaces per-seat tools like Stack Overflow for Teams with a flat-cost instance where you own all the content.
Apache Answer
Graduated as an Apache Software Foundation Top-Level Project with over 15,500 GitHub stars and 100,000+ Docker Hub downloads, Apache Answer delivers the structured Q&A platform that Stack Overflow and Discourse popularized — fully self-hosted under Apache 2.0 with zero vendor lock-in. The Go backend with React frontend serves questions, answers, and knowledge articles with real-time Markdown preview using CommonMark syntax, inline @mentions to ping domain experts, and transparent revision history tracking every edit. Version 2.0 introduced AI workflows including an integrated AI assistant that helps draft and improve answers, a Model Context Protocol server for connecting AI agents to your knowledge base, API key management, and editor plugin support for extending the writing experience. Advanced search filters by tags, usernames, scores, and date ranges, while real-time suggestions surface relevant existing questions as users type to reduce duplicates. The reputation system rewards quality contributions with configurable privilege thresholds, and admin/moderator/user roles control access across the platform. A plugin architecture enables community-built extensions for third-party OAuth login, caching backends, search engines, and storage providers. Theming supports custom layouts, dark mode, and responsive design across devices, with content available in 15+ languages translated by the community. Bulk user import, email domain restrictions, and content access controls secure the platform for enterprise deployment. 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.
Tailchat
Think of it as a team messaging platform where every feature beyond core chat is a plugin you can install or remove, inspired by VS Code's extension model but applied to real-time communication. The Moleculer microservice backend scales horizontally across nodes while Socket.io delivers instant message synchronization with text, images, files, mentions, reactions, and rich Markdown formatting. Available plugins provide LiveKit video conferencing, collaborative drawing boards, task management panels, end-to-end encryption, custom themes, and third-party push notification reception without touching core code. Groups use a two-level space system with customizable panel layouts arranged through drag-and-drop, while role-based access control enforces fine-grained permissions across the organization. The Open Platform exposes OAuth for single sign-on across connected applications and a Bot API enabling bidirectional message processing between Tailchat and external services via HTTP requests. Multi-platform clients cover web, Electron desktop with screenshot capabilities, and mobile apps with native push. Docker Compose deployment bundles MongoDB for persistence, Redis for caching and transport, and MinIO for S3-compatible file storage. Deploy on RepoCloud with a dedicated VPS for persistent team infrastructure under the Apache 2.0 license.
Kanboard
"Less is more" is Kanboard's stated philosophy, and the free, MIT-licensed PHP application lives it: drag tasks between customizable columns, enforce work-in-progress limits per column, and slice boards horizontally with swimlanes for releases, teams, or priorities. Tasks carry what matters - colors, categories, subtasks with time estimates, Markdown descriptions, comments, attachments, internal links, and due dates - and move or duplicate across projects in one click. A concise query language filters any board dynamically (assignee, category, due date, description), and saved filters become custom views. The automatic-actions engine kills repetitive triage: on events like column moves or task creation, Kanboard reassigns, recolors, recategorizes, or closes tasks by rule. Around the board sit a calendar, per-project analytics (cumulative flow, lead and cycle time), Gantt view, and time tracking. Authentication spans LDAP/Active Directory, Google, GitHub, GitLab, and reverse-proxy headers; a JSON-RPC API, webhooks for creating tasks from external systems, and a CLI cover integration. A large community plugin catalog adds what core deliberately omits. With no external dependencies, it runs happily on anything from a Raspberry Pi up - translated into 30+ languages.
Zulip
Used by the Rust language community, NASA, Dropbox, and thousands of organizations worldwide with over 25,600 GitHub stars and 1,500+ contributors, Zulip is the only modern team chat app designed from the ground up for both real-time and asynchronous communication through its unique topic-based threading model where every message belongs to a named topic within a channel. This eliminates the context collapse of linear chat by letting teams follow specific conversations without scrolling through unrelated messages, resume threads days later without losing context, and catch up on missed discussions at per-topic granularity. Server 12.0 introduced end-to-end encryption for mobile push notifications, AI-powered search ranking, channel folders for workspace organization, and expanded video conferencing with Jitsi, BigBlueButton, and Zoom integration. Over 100 native integrations connect GitHub, GitLab, Jira, Sentry, PagerDuty, Travis CI, Redmine, dbt, Nextcloud, and n8n with bidirectional notifications, while LLM-driven agents access web-public channels via a standard llms.txt interface. Full-text search covers unlimited message history across all plans, code blocks render with syntax highlighting for 250+ languages, and LaTeX math expressions display inline. The REST API with typed Python and JavaScript SDKs enables custom bots, webhook integrations, and programmatic administration. Import tools migrate entire workspaces from Slack, Microsoft Teams, Mattermost, and Rocket.Chat. 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.