Immich
Photo Galleries
Photo and video backup solution directly from your mobile phone (alternative to Google Photos).
Actively maintained
Real momentum
AGPL-3.0
The AGPL is the licence most likely to end a fundraise diligence call badly. GPL obligations trigger on distribution; AGPL section 13 extends them to network interaction, which is exactly how SaaS works. Forking an AGPL project into a closed product is a licence breach unless you buy a commercial exception from the copyright holder — which is precisely the business model most AGPL vendors run.
AGPL-3.0 closes the ASP loophole. Serving the software over a network counts as distribution, so your modified source has to be offered to every user of that service. This dataset tracks 307 AGPL projects (18% of 1665 total), 159 of them actively maintained, led by Immich with 111k stars. Verified against repository metadata as of August 2026; this is engineering guidance, not legal advice.
Running the software inside your own company, without redistributing it, is permitted under every licence family here except undeclared/proprietary code.
This is the failure mode. Either the network clause forces your source open, or the licence bans competing commercial services outright.
Restricted. Either derivative work must be released under the same licence, or the licence explicitly forbids commercialising a fork.
| Project | Category | Stars | Maintenance | Licence |
|---|---|---|---|---|
| Immich | Photo Galleries | 111k | Actively maintained | AGPL-3.0 |
| AppFlowy | Task Management & To-do Lists | 75k | Slowing down | AGPL-3.0 |
| AFFiNE Community Edition | Knowledge Management Tools | 72k | Actively maintained | MIT, AGPL-3.0 |
| Plane | Software Development | 56k | Actively maintained | AGPL-3.0 |
| Twenty | Customer Relationship Management (CRM) | 55k | Actively maintained | AGPL-3.0 |
| Mastodon | Communication | 50k | Actively maintained | AGPL-3.0 |
| Metabase | Analytics | 49k | Actively maintained | AGPL-3.0 |
| SiYuan | Knowledge Management Tools | 46k | Actively maintained | AGPL-3.0 |
| Puter | File Transfer & Synchronization | 43k | Actively maintained | AGPL-3.0 |
| PhotoPrism | Photo Galleries | 40k | Actively maintained | AGPL-3.0 |
| TriliumNext Notes | Note-taking & Editors | 37k | Actively maintained | AGPL-3.0 |
| Khoj | Generative Artificial Intelligence (GenAI) | 37k | Actively maintained | AGPL-3.0 |
| Nextcloud | File Transfer & Synchronization | 36k | Actively maintained | AGPL-3.0 |
| Glance | Personal Dashboards | 36k | Slowing down | AGPL-3.0 |
| SearXNG | Search Engines | 36k | Actively maintained | AGPL-3.0 |
| Postiz | Analytics | 35k | Actively maintained | AGPL-3.0 |
| Wiki.js | Wikis | 29k | Slowing down | AGPL-3.0 |
| Plausible Analytics | Analytics | 29k | Actively maintained | AGPL-3.0 |
| Karakeep | Bookmarks and Link Sharing | 28k | Actively maintained | AGPL-3.0 |
| Ente | Photo Galleries | 28k | Actively maintained | AGPL-3.0 |
| Monica | Customer Relationship Management (CRM) | 25k | Abandoned | AGPL-3.0 |
| Firefly III | Money, Budgeting & Management | 24k | Actively maintained | AGPL-3.0 |
| Listmonk | Communication | 23k | Actively maintained | AGPL-3.0 |
| ChartDB | Database Management | 23k | Slowing down | AGPL-3.0 |
| Invidious | Media Streaming | 23k | Actively maintained | AGPL-3.0 |
Photo Galleries
Photo and video backup solution directly from your mobile phone (alternative to Google Photos).
Alternative to Notion, Team knowledge base, Knowledge Bases
Build detailed lists of to-do’s for different projects while tracking the status of each one. Open Source Notion Alternative.
Alternative to Team knowledge base, Knowledge Bases
Next-gen knowledge base that brings planning, sorting and creating all together. Privacy first, customizable and ready to use (alternative to Notion and Miro).
Alternative to Linear, JIRA, Trello, Height, Project Management, Bug tracking
Track issues, epics, and product roadmaps in the simplest way possible (alternative to JIRA, Linear and Height).
Alternative to CRM
A modern CRM offering the flexibility of open source, advanced features, and a sleek design.
Alternative to Social network/ Micro-blogging
Federated microblogging server.
Alternative to Tableau, Power BI, DataStudio, Business intelligence
Easy way for everyone in your company to ask questions and learn from data.
Alternative to Note-taking/ Knowledge management, Note-taking / Personal Knowledge Management
A privacy-first personal knowledge management software, written in typescript and golang.
File Transfer & Synchronization
Web-based operating system designed to be feature-rich, exceptionally fast, and highly extensible.
Photo Galleries
Personal photo management powered by Go and Google TensorFlow. Browse, organize, and share your personal photo collection, using the latest technologies to automatically tag and find pictures.
Note-taking & Editors
Cross-platform hierarchical note taking application with focus on building large personal knowledge bases (fork of Trilium Notes).
Generative Artificial Intelligence (GenAI)
Your AI second brain. Get answers from the web or your docs. Build custom agents, schedule automations, do deep research. Turn any online or local LLM into your personal, autonomous AI.
Alternative to Dropbox, Google Drive, Personal cloud
Access and share your files, calendars, contacts, mail and [more](https://apps.nextcloud.com/) from any device, on your terms.
Personal Dashboards
Highly customizable dashboard that puts all your feeds in one place.
Search Engines
Internet metasearch engine which aggregates results from various search services and databases (Fork of Searx).
Alternative to Buffer, Hootsuite
Schedule posts, track the performance of your content, and manage all your social media accounts in one place (Alternative to Buffer, Hootsuite, Sprout Social).
Wikis
Modern, lightweight and powerful wiki app using Git and Markdown.
Alternative to Google Analytics, Web analytics
Simple, lightweight (< 1 KB) and privacy-friendly web analytics.
Bookmarks and Link Sharing
Bookmark-everything app with a touch of AI for the data hoarders out there.
Photo Galleries
An end-to-end encrypted photo-sharing platform (alternative to Google Photos, Apple Photos).
Customer Relationship Management (CRM)
Personal relationship manager, and a new kind of CRM to organize interactions with your friends and family.
Alternative to Personal finance
Firefly III is a modern financial manager. It helps you to keep track of your money and make budget forecasts. It supports credit cards, has an advanced rule engine and can import data from many banks
Alternative to Newsletters
High performance, self-hosted newsletter and mailing list manager with a modern dashboard.
Database Management
Database diagrams editor that allows you to visualize and design your DB with a single query.
Media Streaming
Alternative YouTube front-end.
Web Servers
Identity-aware tunneled reverse proxy with dashboard UI, access control, and WireGuard-based tunnels (alternative to Cloudflare Tunnel, Tailscale).
Alternative to Team knowledge base
Collaborative wiki and documentation software (alternative to Confluence, Notion).
Alternative to 1Password
Password manager with a webapp, browser extension, and mobile app.
Communication
The most private and secure chat and applications platform - now with double ratchet E2E encryption.
Games
Ad-less chess server powering lichess.org, with official iOS and Android client apps.
Miscellaneous
Online file converter which supports over a thousand different formats.
Alternative to DocuSign
Create, fill, and sign digital documents (alternative to DocuSign).
Note-taking & Editors
Web-based collaborative LaTeX editor.
Miscellaneous
Machine Translation API.
Feed Readers
Self-hostable RSS feed aggregator.
Media Streaming
Decentralized video streaming platform using P2P (BitTorrent) directly in the web browser.
File Transfer & Synchronization
File hosting and sharing solution primary for teams and organizations.
Document Management
Powerful, privacy-first, client-side PDF toolkit that allows you to manipulate, edit, merge, and process PDF files directly in your browser.
Communication
Link aggregator for the fediverse (alternative to Reddit).
Alternative to DocuSign, Document signing
Digital document signing platform (alternative to DocuSign).
Alternative to Dropbox, Google Drive
Web file manager that lets you manage your data anywhere it is located: FTP, SFTP, WebDAV, Git, S3, Minio, Dropbox, or Google Drive.
Media Management
Web GUI for youtube-dl, with playlist support. Allows downloading videos from dozens of websites.
Communication
All-in-one mail server with JMAP, IMAP4, and SMTP support and a wide range of modern features.
Software Development
Remote development machines on your own infrastructure.
Alternative to Workflow automation
Business automation tool that lets you connect different services like Twitter, Slack, and more to automate your business processes (alternative to Zapier).
Communication
Distributed social networking server.
Media Streaming
A web-based library organizer and player for your adult media stash, with auto-tagging and metadata scraping support.
Alternative to Typeform, Google Forms, React Hook Form, Online forms
Experience Management Suite built on the largest open source survey stack worldwide. Gracefully gather feedback at every step of the customer journey to know what your customers need.
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AGPL-3.0 closes the ASP loophole. Serving the software over a network counts as distribution, so your modified source has to be offered to every user of that service. The AGPL is the licence most likely to end a fundraise diligence call badly. GPL obligations trigger on distribution; AGPL section 13 extends them to network interaction, which is exactly how SaaS works. Forking an AGPL project into a closed product is a licence breach unless you buy a commercial exception from the copyright holder — which is precisely the business model most AGPL vendors run.
307 of 1665 tracked projects carry a AGPL licence — about 18%. 159 of them show real momentum (commits in most of the last twelve months plus a recent release), so the practical shortlist is smaller than the raw count suggests.
Licence breach is copyright infringement, and the usual consequence is not a lawsuit — it is a failed diligence review. Acquirers and Series A investors run automated licence scans over your dependency tree; an unresolved copyleft or source-available dependency in a closed product either delays the deal or gets priced into it. The cheap fix is choosing correctly at week one.
Yes — AGPL is an OSI-approved open-source licence family. What varies is the obligation that comes attached, not whether the code is open.
Licence data comes from repository metadata and can lag a relicensing event. Confirm the LICENSE file in the repository before shipping. This page is engineering guidance, not legal advice.
IdeaProof checks whether your idea is already built, how saturated the category is, and where the remaining wedge sits — in about two minutes.
Validate your idea freeSearch this database by category and by the commercial product you would replace. It covers 1665 projects across 130 categories, each mapped to the paid tool it substitutes. If your category shows a "Crowded" verdict, a maintained free version almost certainly exists and your positioning has to account for it.
No. It means free is your price anchor. Plenty of large companies were built next to a good open-source project — the ones that failed were the ones selling the same job at a price the free tool made indefensible. Find the part of the job the project deliberately does not do, and sell that.
Each category gets a 0–100 score built from three inputs: how many implementations exist, what share of them are still actively maintained, and how far ahead the leading project is compared with the category median. 62+ is Crowded, 38–61 Contested, under 38 Open. 11 categories are Crowded and 88 are Open.