Fair-code workflow automation built for technical teams — self-host or use the cloud.
Open sourceSelf-hostFree / self-hostSustainable Use License194.6k★
- Unlimited workflow runs when self-hosted — no per-task billing
- Code nodes let developers drop into JS or Python for anything the UI can't express
- Fair-code license (Sustainable Use) restricts commercial redistribution of the source
Open-source Firebase alternative built on Postgres with auth, storage, realtime, and edge functions.
Open sourceSelf-hostFree / self-hostApache-2.0105k★
- Full SQL and the entire Postgres extension ecosystem — no NoSQL trade-offs
- Apache-2.0 licensed and self-hostable with a single Docker Compose command
- Free tier pauses inactive projects after one week, breaking always-on demos
Open-source, peer-to-peer continuous file synchronization with no central server required.
Open sourceSelf-hostFree / self-hostMPL-2.086k★
- Zero recurring cost and zero third party — files sync directly between your own devices
- MPL-2.0 licensed, actively developed since 2013 with 86k+ GitHub stars
- No web-based file browser, sharing links, or public link sharing — it's device sync, not a storage portal
Open-source, local-first Notion alternative built in Rust and Flutter with full self-hosting support.
Open sourceSelf-hostFree / self-hostAGPL-3.073.1k★
- AGPL-licensed core with true local-first storage and full offline support
- Native desktop apps on macOS, Windows, and Linux built with Flutter
- Database feature set is less mature than Notion's — rollups and complex formulas are still catching up
Open-source local-first workspace merging a rich document editor, an infinite whiteboard, and a structured database.
Open sourceSelf-hostFree / self-hostMIT / Custom69.9k★
- Unique whiteboard-meets-document approach covers brainstorming and structured writing in one tool
- Local-first CRDT engine means your data exists on disk before any sync
- Younger project than Notion or AppFlowy — some database features remain early-access
Turn any MySQL, Postgres, SQLite or SQL Server database into a smart spreadsheet UI.
Open sourceSelf-hostFree / self-hostAGPL-3.0 / Open-core63.7k★
- Works with databases you already own — no data migration required
- Both REST and GraphQL APIs generated automatically for every table
- AGPL-3.0 license complicates embedding in proprietary SaaS without a commercial license
Single-file open-source backend — SQLite, auth, realtime, and admin UI packed into one Go binary.
Open sourceSelf-hostFree / self-hostMIT59.3k★
- Zero external dependencies — one binary is the entire production backend
- Tiny resource footprint runs comfortably on a $5/month VPS or a Raspberry Pi
- SQLite write concurrency ceiling makes it unsuitable for high-write production workloads
Lightning-fast, typo-tolerant open-source search engine with exceptional developer experience.
Open sourceSelf-hostFree / self-hostMIT58.4k★
- MIT-licensed core — free to self-host with no record or query caps
- One-binary deployment with a straightforward REST API
- Entire index held in memory — RAM requirements grow with dataset size
Open-source self-hostable platform to deploy apps, databases, and services on your own servers.
Open sourceSelf-hostFree / self-hostApache-2.057.5k★
- Free and self-hostable — one VPS replaces unlimited Heroku dynos
- Web UI covers the full deploy lifecycle without touching the CLI
- Laravel/PHP stack can be heavyweight compared to minimal PaaS alternatives
Open-source BaaS with auth, databases, storage, functions, and messaging in a self-hosted package.
Open sourceSelf-hostFree / self-hostBSD-3-Clause56.4k★
- Broad SDK coverage across mobile, web, and cross-platform frameworks under one consistent API
- Built-in messaging for push, email, and SMS removes a common third-party integration
- Managed cloud platform is newer and smaller than Supabase's with fewer global regions
Open-source project management platform in the style of Linear, Jira, and Asana.
Open sourceSelf-hostFree / self-hostAGPL-3.053.6k★
- Fast, modern UI that mirrors Linear's keyboard-driven workflow
- Free self-hosted Community edition with no user cap
- AGPL-3.0 core means any modified, network-served fork must publish its source
Modern open-source CRM with a Notion-style UI and developer-first architecture.
Open sourceSelf-hostFree / self-hostAGPL-3.051.9k★
- Clean, modern UI that feels fast and uncluttered
- Fully customizable data model without needing a consultant
- Relatively young project — some enterprise features still maturing
Open-source scheduling infrastructure for individuals and teams — self-host or use the cloud.
Open sourceSelf-hostFree / self-hostAGPL-3.046k★
- Self-hostable with full data ownership under AGPL
- Generous free cloud tier for individuals
- Self-hosting requires a PostgreSQL database and more infrastructure than a hosted SaaS
Open-source team chat and omnichannel customer messaging platform.
Open sourceSelf-hostFree / self-hostMIT45.7k★
- MIT license with a large feature set available for free on self-hosted installs
- Omnichannel capabilities blend internal chat and external customer communications
- JavaScript/Meteor stack can be resource-intensive compared to lighter alternatives
Open-source low-code framework for building internal apps, admin panels, and dashboards.
Open sourceSelf-hostFree / self-hostApache-2.040.2k★
- Apache-2.0 license with no restrictions on the core
- Self-hostable on any infra, including air-gapped environments
- UI feels less polished than Retool out of the box
Fast, collaborative team wiki with Markdown editing, nested collections, and a self-hostable server.
Open sourceSelf-hostFree / self-hostBSL 1.139.1k★
- Clean, fast reading and writing experience purpose-built for team wikis
- Self-hostable with Docker — source available under BSL with a one-year delay to open source
- BSL license means commercial redistribution is restricted; it is not classic OSI open source
Open-source, self-hosted team messaging built for security-conscious and DevOps teams.
Open sourceSelf-hostFree / self-hostMIT / Open-core38.3k★
- Full data sovereignty — runs on your own servers with no vendor access
- MIT-licensed core is free to self-host with no seat caps
- UI and mobile experience lag behind Slack's polish
Open-source low-code framework to build and deploy internal tools with minimal engineering effort.
Open sourceSelf-hostFree / self-hostAGPL-3.0 / Open-core38.1k★
- AGPL core is freely self-hostable without per-seat restrictions
- Built-in ToolJet DB gives teams a managed Postgres table editor out of the box
- AGPL license requires open-sourcing modifications if distributed, which complicates enterprise use
Simple, self-hostable analytics with MIT licensing, no pageview caps, and a free cloud tier.
Open sourceSelf-hostFree / self-hostMIT37.4k★
- MIT license — fully free to self-host with no feature gates or pageview limits
- Deploys in minutes to Vercel or any Node host without operational complexity
- No native funnels, session replay, or A/B testing capabilities
Open-source, self-hosted file sync, sharing, and collaboration suite.
Open sourceSelf-hostFree / self-hostAGPL-3.036k★
- Broadest feature set of any self-hosted storage platform — sync, office docs, chat, calendar in one
- Massive community and app ecosystem (a decade of continuous development)
- PHP stack with many moving parts (Redis, cron, optional Collabora container) makes tuning nontrivial at scale
Battle-tested open-source identity and access management with SSO, OIDC, and SAML.
Open sourceSelf-hostFree / self-hostApache-2.035.4k★
- Apache-2.0 licensed — completely free with no seat or MAU limits
- CNCF-incubating project with Red Hat backing and a decade of production hardening
- Java-based stack is resource-heavy and slow to cold-start compared to modern alternatives
Open-source product analytics suite with events, funnels, session replay, feature flags, and A/B tests.
Open sourceSelf-hostFree / self-hostMIT35.2k★
- Single platform replaces GA, Hotjar, LaunchDarkly, and parts of Segment
- Generous free cloud tier — 1 million events per month at no cost
- Self-hosting at scale requires Kafka, ClickHouse, and Redis — significant ops burden
Minimalist self-hosted PaaS powered by Docker — git push to deploy on a single Linux server.
Open sourceSelf-hostFree / self-hostMIT32k★
- Extremely lightweight — minimal resource overhead on a single server
- MIT-licensed with a decade of production battle-testing
- No web UI — every operation is CLI or SSH, which raises the floor for non-developers
Open-source low-code platform with a built-in database for building internal apps fast.
Open sourceSelf-hostFree / self-hostGPL-3.0 / Open-core28.1k★
- Built-in database removes the need to provision a separate data store for simple apps
- GPL core is freely self-hostable with no seat limits
- BudibaseDB is not suitable for high-volume transactional workloads
Lightweight, cookieless web analytics that is GDPR-friendly out of the box.
Open sourceSelf-hostfrom $9/moAGPL-3.027.4k★
- No cookies means legally simpler GDPR/CCPA compliance without a consent flow
- Sub-1 KB tracking script with no measurable page-weight impact
- No session replay, heatmaps, or multi-step funnel visualization
Open-source all-in-one project management platform combining issues, docs, and chat.
Open sourceSelf-hostFree / self-hostEPL-2.026.4k★
- Genuinely replaces several tools at once (PM + docs + chat) in a single self-hosted stack
- Fast, modern UI comparable to Linear/Notion
- Huly Inc discontinued its own hosted cloud service in 2026 — self-hosting is now the only supported path
Open-source, self-hosted kanban and table boards in the style of Trello and Notion.
Open sourceSelf-hostFree / self-hostMIT26.3k★
- Genuinely lightweight — a single binary can run a personal server
- MIT licensed with no paid tier or feature gate at all
- Mattermost stopped actively developing it in 2023; it's now community-maintained only
Open-source, in-memory typo-tolerant search engine optimized for millisecond performance.
Open sourceSelf-hostFree / self-hostGPL-3.026.1k★
- Exceptionally low and predictable query latency due to pure in-memory architecture
- Algolia-compatible InstantSearch adapter makes migration straightforward
- GPL-3.0 license requires careful review for proprietary commercial products
MIT-licensed no-code automation platform with an AI-first design and clean Zapier-like interface.
Open sourceSelf-hostFree / self-hostMIT23.1k★
- Pure MIT license — no commercial-use restrictions unlike n8n's fair-code terms
- No-code-first UX makes it accessible to non-developers
- Smaller connector library than Zapier or n8n today
Modern open-source identity provider with a clean UI, supporting SSO, OIDC, SAML, and LDAP.
Open sourceSelf-hostFree / self-hostMIT / Open-core22.2k★
- Significantly friendlier admin UX than Keycloak — less XML, no realm mental model
- MIT-licensed community edition is free with no MAU or seat limits
- Enterprise features (audit logs, support SLAs) require a paid license
Self-hosted, high-performance newsletter and mailing-list manager — pair with any SMTP provider.
Open sourceSelf-hostFree / self-hostAGPL-3.021.9k★
- Zero per-contact or per-send cost — pay only for SMTP delivery
- Single Go binary with PostgreSQL — trivial to run on a cheap VPS
- No hosted/managed version — you own infrastructure, backups, and deliverability
Open-source no-code database built natively on Postgres — real-time, API-first, and Airtable-compatible.
Open sourceSelf-hostFree / self-hostAGPL-3.021.4k★
- Pure Postgres-native storage means you can query Teable data directly via SQL
- Real-time collaboration built in from the ground up, not added on
- Younger project with a smaller community and integration ecosystem than NocoDB or Baserow
Open-source Trello-style kanban board, self-hosted with Meteor and MongoDB.
Open sourceSelf-hostFree / self-hostMIT21k★
- MIT licensed, completely free with no paid tier ever
- Very close Trello feature/UI parity, so migration is nearly frictionless
- Meteor + MongoDB stack is heavier to self-host than newer Go/Node single-binary tools
Open-source developer platform that turns scripts into production workflows, scheduled jobs, and internal UIs.
Open sourceSelf-hostFree / self-hostAGPL-3.017k★
- Scripts are first-class citizens — no shoehorning real code into config-file automation
- App builder turns backend scripts into shareable internal tools with zero frontend work
- AGPL license requires derivative works to be open-sourced unless using a commercial license
Open-source project management with Gantt charts, agile boards, and enterprise governance.
Open sourceSelf-hostFree / self-hostGPL-3.015.5k★
- Genuinely strong Gantt/roadmap view — rare in open-source PM tools
- Mature permissions model suited to regulated or public-sector teams
- Ruby on Rails stack feels heavier and slower than newer Node/Go tools
Open-source authentication with session management, social login, and passwordless — self-host or managed.
Open sourceSelf-hostFree / self-hostApache-2.015.1k★
- Apache-2.0 licensed core is free to self-host with no MAU or seat limits
- Recipe-based architecture lets you mix and match auth methods modularly
- Enterprise features like SAML SSO and SCIM provisioning require the paid managed plan
Open-source self-hosted PaaS with a web dashboard, Docker Swarm orchestration, and one-click app templates.
Open sourceSelf-hostFree / self-hostApache-2.015.1k★
- Web UI makes self-hosted PaaS accessible to teams unfamiliar with terminal deployments
- One-click app catalog covers most common open-source stacks instantly
- Docker Swarm is less popular than Kubernetes for large-scale production workloads
Open-source file sync and share platform built for sync performance at scale.
Open sourceSelf-hostFree / self-hostAGPL-3.014.9k★
- Noticeably faster sync than Nextcloud on large files and big libraries, by design
- Client-side encrypted libraries for genuine zero-knowledge storage
- Written in C with a narrower plugin ecosystem than Nextcloud's PHP app store
Open-source web file manager that puts a modern UI in front of storage you already have.
Open sourceSelf-hostFree / self-hostAGPL-3.014.3k★
- Connects to storage you already run instead of requiring a data migration
- Broadest backend/connector list of any tool in this category (S3, SMB, FTP, Drive, and more)
- It's a UI/gateway layer, not a storage engine — you still need underlying storage (S3, SMB, etc.) configured
Open-source DocuSign alternative for self-hosted digital document signing with no per-envelope fees.
Open sourceSelf-hostFree / self-hostAGPL-3.013.6k★
- AGPL-licensed with full self-hosting — signing data never leaves your own infrastructure
- Per-seat cloud pricing with no per-document or per-envelope fees at any volume
- AGPL-3.0 license requires sharing modifications if you distribute the software commercially
Open-source experience-management platform for targeted in-app and link surveys.
Open sourceSelf-hostFree / self-hostAGPL-3.012.5k★
- AGPL core is free with unlimited responses on self-hosted deployments
- Event-based targeting lets you survey specific user cohorts at precise moments
- AGPL license requires open-sourcing modifications if distributed commercially
Open-source project management built around goals and lean/agile methodology, not just tasks.
Open sourceSelf-hostFree / self-hostAGPL-3.010.1k★
- Unusual goals-first structure connects daily tasks back to strategy explicitly
- Genuinely accessibility-conscious design, documented as a project priority
- Smaller community and plugin ecosystem than Plane, Redmine, or OpenProject
Minimalist, self-hosted kanban board with a single-file PHP install.
Open sourceSelf-hostFree / self-hostMIT9.7k★
- Extremely lightweight — runs comfortably on a $5/mo VPS with SQLite
- MIT licensed, zero paid tier, no telemetry
- Project is in maintenance mode — mostly bug fixes, few new features since 2023
Long-running open-source project management and issue tracker built on Ruby on Rails.
Open sourceSelf-hostFree / self-hostGPL-2.06k★
- Extremely mature and stable — running in production since 2006
- Enormous third-party plugin and theme ecosystem
- UI is dated and configuration-heavy compared to modern tools
Open-source no-code database you can self-host, with a familiar Airtable-style UI.
Open sourceSelf-hostFree / self-hostMIT / Open-core5.2k★
- MIT-licensed core you can run for free
- One-command Docker self-hosting
- Some advanced features are paid/enterprise
Open-source event ingestion and data pipeline that streams clicks, events, and identities straight to your warehouse.
Open sourceSelf-hostFree / self-hostMIT4.8k★
- MIT license — freely self-hostable with full source access and no usage-based billing
- ClickHouse-native support delivers sub-second query performance on billions of events
- Primarily an ingestion layer — lacks Segment's breadth of 400+ maintained destination connectors
Open-source to-do and task management app you can self-host in one Go binary.
Open sourceSelf-hostFree / self-hostAGPL-3.04.6k★
- Single Go binary self-hosting — no external database required for small installs
- Genuinely covers both personal to-do lists and small-team project boards
- AGPL-3.0 licensed, which restricts commercial SaaS resale of a modified version
Open-source customer data platform built around the warehouse, with self-hosting and 200+ destinations.
Open sourceSelf-hostFree / self-hostAGPL-3.0 / Open-core4.4k★
- AGPL core is self-hostable with no event-volume billing on your own infra
- Segment-compatible API makes migration a drop-in replace for instrumentation
- AGPL license requires open-sourcing modifications to the server if distributed externally
Mature, self-hostable open-source CRM with deeply customizable entities and business-process automation.
Open sourceSelf-hostFree / self-hostAGPL-3.03.1k★
- Battle-tested codebase with over a decade of production use
- Highly customizable without needing to modify core code
- PHP/legacy stack is less attractive to modern JavaScript developers
Open-source content collaboration and file-sharing platform built on a Go microservices core.
Open sourceSelf-hostFree / self-hostAGPL-3.02.2k★
- Rebuilt from the original Pydio PHP codebase into a modern Go microservices stack (Cells)
- Workflow engine lets you trigger automations on file events without external tooling
- Smaller community and slower release cadence than Nextcloud or Seafile
Open-source file sync and share platform, rebuilt in Go for large-scale deployments.
Open sourceSelf-hostFree / self-hostApache-2.02k★
- Apache-2.0 licensed — the most permissive license of any tool in this category
- Go microservices architecture scales and deploys more predictably than legacy PHP ownCloud
- Much younger rewrite than Nextcloud or Seafile — smaller community and fewer third-party integrations
Free, open-source client file-sharing portal built for sending files to customers, not team sync.
Open sourceSelf-hostFree / self-hostGPL-2.01.9k★
- Completely free with no paid tier, ever, under GPL-2.0
- Purpose-built for client-facing file exchange rather than internal team sync
- Not a sync tool — there's no desktop client or continuous folder sync, just web upload/download
Spreadsheet-database hybrid for building collaborative apps and trackers.
Proprietaryfrom $20/moProprietary
- Polished, beginner-friendly interface
- Huge ecosystem of templates and integrations
- Per-seat pricing scales painfully for larger teams
Hosted search-as-a-service API delivering fast, relevant search with minimal setup.
ProprietaryFree / self-hostProprietary
- Extremely fast global performance with zero infrastructure to manage
- Well-documented SDKs and UI component libraries speed up integration
- Costs scale quickly — pricing is based on both records and search operations
Cloud project management for tracking tasks, projects, and cross-team work.
Proprietaryfrom $11/moProprietary
- Polished, fast UI with a genuinely short learning curve
- Strong cross-project reporting via Portfolios and Goals
- Per-seat pricing with a 2-seat minimum on paid tiers
Identity-as-a-service platform for adding authentication and authorization to any application.
Proprietaryfrom $35/moProprietary
- Fastest path to production-grade auth — SDKs for every major language and framework
- Handles compliance edge-cases (MFA, adaptive auth, brute-force protection) out of the box
- MAU-based pricing escalates sharply past the free tier, especially after Okta acquisition
Automated scheduling tool that eliminates meeting coordination back-and-forth.
Proprietaryfrom $10/moProprietary
- Polished, frictionless booking experience for invitees
- Wide integration ecosystem covering most business tools
- Per-seat pricing makes team deployments expensive fast
Market-leading e-signature platform trusted by enterprises for legally binding document workflows.
Proprietaryfrom $10/moProprietary
- Widely recognized brand gives recipients immediate trust before they open the document
- Deep native integrations with Salesforce, SAP, and Microsoft 365 require no custom code
- Per-envelope allowances on lower plans fill up quickly; overage charges are not prominently flagged
Cloud file storage and sync with sharing, e-signature, and backup add-ons.
Proprietaryfrom $12/moProprietary
- Best-in-class sync reliability and conflict handling
- Simple sharing UX that non-technical recipients understand instantly
- $11.99/mo (Plus, 2TB) minimum for a real personal plan, scaling fast for teams
Google's all-in-one BaaS platform with Firestore, Auth, hosting, and serverless functions.
ProprietaryFree / self-hostProprietary
- Generous Spark free tier covers most prototype and small-app needs with no credit card
- Native iOS and Android SDKs handle offline caching and sync automatically
- Vendor lock-in to Google infrastructure with no self-hosting or data export path
Google's dominant web analytics platform, now built on the event-based GA4 model.
ProprietaryFree / self-hostProprietary
- Free for most websites with extremely generous traffic limits
- Tight integration with Google Ads, Looker Studio, and Search Console
- Requires cookie consent banners under GDPR, adding compliance overhead
Managed cloud application platform that lets you deploy, run, and scale apps without managing servers.
Proprietaryfrom $5/moProprietary
- Zero infrastructure configuration — git push and it runs
- Massive add-on marketplace covers most backend needs
- Free tier was removed in November 2022, raising the floor cost
All-in-one email marketing platform for campaigns, automations, and audience growth.
Proprietaryfrom $13/moProprietary
- Beginner-friendly interface with a very shallow learning curve
- Strong template library and design tools for non-designers
- Contact-based pricing escalates steeply — billed on total list size including unsubscribes
All-in-one connected workspace combining docs, wikis, and databases in a single flexible canvas.
Proprietaryfrom $10/moProprietary
- Highly flexible page model adapts to docs, project trackers, CRMs, and wikis equally well
- Polished cross-platform apps with reliable real-time collaboration
- No self-hosting option — all data lives on Notion's servers with no local-first mode
Low-code platform for building internal tools and admin panels using drag-and-drop components.
Proprietaryfrom $10/moProprietary
- Fastest path from a database query to a working admin UI
- Deep connector library reduces integration boilerplate
- Per-user billing escalates sharply as team grows
Enterprise CRM and cloud platform for sales, service, and marketing automation.
Proprietaryfrom $25/moProprietary
- Deeply configurable to match almost any sales process
- Vast ecosystem of integrations, partners, and certified consultants
- Per-seat subscription pricing becomes very expensive for growing teams
Customer data platform that collects events from every touchpoint and routes them to your tools.
ProprietaryFree / self-hostProprietary
- Widest destination catalog in the category — 400+ integrations maintained by Segment
- Segment.io analytics.js is the de-facto industry standard event schema
- Event-volume billing grows steeply with traffic — warehouse-first alternatives often cheaper at scale
Cloud-hosted team messaging and channels platform, owned by Salesforce.
Proprietaryfrom $7.25/moProprietary
- Best-in-class UX and near-universal adoption makes onboarding new hires trivial
- Enormous app ecosystem covers almost every SaaS integration
- Per-user billing escalates steeply as headcount grows
Notion-like form builder with unlimited free forms and responses on the free plan.
Proprietaryfrom $29/moProprietary
- Genuinely unlimited forms and responses at no cost — rare in the category
- Block editor makes complex form layouts fast to build without a learning curve
- Tally branding appears on free-plan forms and cannot be removed without upgrading
Conversational online forms and surveys with a distinctive one-question-at-a-time flow.
Proprietaryfrom $25/moProprietary
- Conversational UI consistently outperforms traditional form layouts for completion rates
- Polished visual design requires no customization to look professional
- Response limits on lower-tier plans push active users to expensive subscriptions quickly
Hosted automation platform connecting 6,000+ apps via point-and-click Zaps.
Proprietaryfrom $20/moProprietary
- Largest integration library in the category by far
- No technical knowledge needed to build most workflows
- Per-task metering makes high-volume automation expensive fast