Updated August 2026 · 1665 projects
    130 categories · 110 paid tools mapped

    Is Your Idea Already Built?

    Check any idea against 1665 open-source projects before you write a line of code. Every project scored on maintenance, licence and momentum — because a free tool nobody maintains is not competition, and a free tool that ships weekly is.

    736 with real momentum · 149 dead or dying · 11 saturated categories

    By IdeaProof Research Team · Updated August 2026

    Glass code editor window surrounded by floating repository, star and growth cards
    TL;DR • open source alternatives • as of August 2026

    Before you build, check whether a maintained free version already exists. This database tracks 1665 open-source projects across 130 categories, mapped to the 110 commercial products they replace. 736 have real momentum (commits in most of the last twelve months plus a recent release); 149 are dormant or abandoned despite still looking popular. 11 categories are saturated and 88 still have room.

    Saturation verdict by category

    130 categories scored on implementation count, maintenance rate and how far ahead the leader is.

    Communication

    Crowded

    177 projects · 100 maintained · leader Mastodon

    Software Development

    Crowded

    100 projects · 58 maintained · leader Dify.ai

    Altro

    Contested

    96 projects · 0 maintained · leader 11ty

    Miscellaneous

    Crowded

    76 projects · 40 maintained · leader revealjs

    Media Streaming

    Crowded

    62 projects · 36 maintained · leader Jellyfin

    File Transfer

    Crowded

    58 projects · 28 maintained · leader copyparty

    Content Management Systems (CMS)

    Crowded

    44 projects · 29 maintained · leader Strapi

    Money, Budgeting & Management

    Crowded

    42 projects · 27 maintained · leader HyperSwitch

    Document Management

    Crowded

    41 projects · 22 maintained · leader Stirling-PDF

    Games

    Crowded

    40 projects · 20 maintained · leader Sunshine

    Analytics

    Crowded

    38 projects · 18 maintained · leader Superset

    Automation

    Crowded

    34 projects · 15 maintained · leader n8n

    E-commerce

    Contested

    28 projects · 17 maintained · leader MedusaJs

    Self-hosting Solutions

    Open

    27 projects · 8 maintained · leader Umbrel

    Media Management

    Contested

    26 projects · 13 maintained · leader Sonarr

    Wikis

    Contested

    26 projects · 12 maintained · leader Outline

    Photo Galleries

    Contested

    25 projects · 15 maintained · leader Immich

    Feed Readers

    Contested

    24 projects · 11 maintained · leader RSSHub

    Task Management & To-do Lists

    Contested

    24 projects · 9 maintained · leader AppFlowy

    Pastebins

    Contested

    21 projects · 9 maintained · leader PrivateBin

    Ticketing

    Open

    21 projects · 10 maintained · leader Zammad

    Database Management

    Contested

    20 projects · 11 maintained · leader NocoDB

    File Transfer & Synchronization

    Contested

    20 projects · 14 maintained · leader Syncthing

    Internet of Things (IoT)

    Contested

    20 projects · 10 maintained · leader Home Assistant

    Note-taking & Editors

    Contested

    20 projects · 14 maintained · leader Memos

    Polls and Events

    Contested

    19 projects · 8 maintained · leader Formbricks

    Web Servers

    Contested

    19 projects · 14 maintained · leader Caddy

    Bookmarks and Link Sharing

    Contested

    18 projects · 9 maintained · leader Karakeep

    Maps and Global Positioning System (GPS)

    Contested

    18 projects · 13 maintained · leader Dawarich

    Personal Dashboards

    Contested

    18 projects · 10 maintained · leader Glance

    Search Engines

    Contested

    16 projects · 11 maintained · leader ElasticSearch

    Blogging Platforms

    Contested

    15 projects · 4 maintained · leader Ghost

    Learning and Courses

    Open

    15 projects · 2 maintained · leader Canvas LMS

    Archiving and Digital Preservation (DP)

    Contested

    14 projects · 9 maintained · leader ArchiveBox

    Generative Artificial Intelligence (GenAI)

    Contested

    14 projects · 12 maintained · leader Ollama

    Groupware

    Open

    13 projects · 2 maintained · leader Colanode

    The 5-step open source competition check

    1. 1. Search the category, not the product name

      Founders check whether their exact product exists and stop there. Search the category instead: the thing that kills a launch is not an identical clone, it is a maintained free tool that solves 80% of the same job well enough that nobody pays for the other 20%.

    2. 2. Separate popularity from maintenance

      Stars never decay. 149 projects here are dormant or abandoned while still carrying thousands of stars. Look at commits in the last twelve months, months with any commit, and the date of the last release — those three tell you whether the project is a competitor or a corpse.

    3. 3. Read the licence before you plan a business model

      A permissive licence means someone can fork your open competitor and sell it — including you. An AGPL project blocks closed SaaS wrappers. A source-available licence is not open source at all. The licence decides whether 'commercialise the open tool' is a strategy or a lawsuit.

    4. 4. Price against free, not against the incumbent

      If a maintained free alternative exists, your real competitor is not the paid incumbent — it is the cost of self-hosting. Quantify what a team actually spends running the free version (hosting, upgrades, on-call, integrations) and price under that number, not under the incumbent's list price.

    5. 5. Pick a wedge open source structurally cannot copy

      Volunteer projects rarely deliver enterprise compliance, guaranteed response times, managed migrations, done-for-you onboarding or vertical-specific workflows. Those are the durable wedges. 'Nicer UI' is not one — it gets copied in a weekend.

    How to compete when a free version already exists

    Why 'someone already built it' is the wrong conclusion

    Existence is not competition. A project competes with you only if it is maintained, findable, deployable by your buyer and licensed for their use. Most projects fail at least one of those tests. Run all four before you shelve an idea — or before you assume you have a clear run.

    • Maintained: commits in the last twelve months and a recent release.
    • Findable: your buyer can discover it without knowing the project name.
    • Deployable: the buyer's team can actually run it without a platform engineer.
    • Licensed: the licence permits the use your buyer needs.

    How stars mislead founders

    Stars are a lifetime counter with no decay, so a project abandoned in 2022 still looks like a leader in 2026. In this dataset 149 projects are dormant, abandoned or archived, and several of them sit in the top decile by stars. Sort by momentum and commit activity instead — popularity tells you the project was once interesting, maintenance tells you whether it will still be there when your customer needs a bug fixed.

    The self-hosting cost buyers forget to count

    When a prospect says 'we could just self-host the free one', they are usually comparing your price against zero. The real comparison is your price against hosting, upgrades, backups, security patching, integration work and the engineer hours behind all of it. Quantifying that number is the single most effective response to a free-alternative objection — and it is more persuasive coming with a spreadsheet than with a feature list.

    • Infrastructure: compute, storage, backups, monitoring.
    • Upgrades: breaking releases, migration work, dependency drift.
    • Security: patching, access control, audit trails, compliance evidence.
    • Opportunity cost: engineer time not spent on your buyer's actual product.

    Licences decide business models

    Founders treat licensing as a legal footnote and then discover it dictates strategy. Permissive licences allow closed commercial forks, which is why so many managed services exist around MIT and Apache projects — and also why your differentiation cannot be the code itself. Copyleft licences, especially AGPL, remove the closed-wrapper option entirely, which reduces competition but restricts you too. Source-available licences exist precisely to stop the wrapper business.

    Where the openings actually are

    88 of 130 categories in this dataset are still Open: few implementations, weak maintenance rates, no dominant leader. Thin open-source coverage is a signal, not a guarantee — volunteers avoid categories that are boring, heavily regulated, or expensive to run as much as they avoid categories nobody wants. The regulated and expensive ones are where a commercial product wins; the boring ones are where you validate demand first.

    How to use this before writing code

    Look up your category, read the verdict, then open the two or three maintained leaders and read their issue trackers. The feature requests maintainers keep declining are the clearest map of what a paid product can own. Then validate that the people asking will pay — an unmet request in an open-source tracker proves demand exists, not that it has budget.

    Open source competition: common questions

    How do I know if my startup idea already exists as open source?

    Search 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.

    Does an open-source alternative mean I should not build my product?

    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.

    What does the saturation score mean?

    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.

    How is 'real momentum' calculated?

    A project has momentum when it committed code in most of the last twelve months, shipped a release recently and is not archived. 736 of 1665 projects qualify. This is the single most useful filter here — it strips out the popular-but-dead repositories that make a category look more competitive than it is.

    Can I use an open-source project commercially?

    It depends entirely on the licence. MIT, Apache and BSD let you build and sell closed products on top. GPL and AGPL require derivative work to stay open, and AGPL extends that to network use, which blocks most SaaS wrappers. BSL, SSPL and Commons Clause are source-available, not open source, and usually restrict competing commercial use outright.

    What is the difference between open source and self-hosted?

    Open source describes the licence; self-hosted describes where it runs. Most projects here are both, but some open-source tools are only practical as a managed service, and some self-hostable products are commercially licensed. Buyers comparing you against a 'free' option are usually comparing against a self-hosted deployment plus its maintenance cost.

    How often is this dataset updated?

    Repository metadata — stars, commit cadence, last release, archive flag and licence — was last refreshed in August 2026. Projects whose metadata could not be fetched are labelled "Not verified" rather than silently assumed healthy.

    Where does the data come from?

    Public GitHub repository metadata, cross-referenced with curated public lists of open-source alternatives and self-hosted software. Every project row keeps its source list, and the commercial-product mapping comes from the alternative lists themselves rather than being inferred.