Memos
Note-taking & Editors
Knowledge base that works with a SQLite db file.
Actively maintained
Real momentum
MIT
Every open-source note-taking & editors project we track, scored on maintenance, momentum and licence — so you can tell the live competitors from the abandoned repositories.
Note-taking & Editors has 20 open-source implementations in this dataset, of which 14 show real momentum and 1 are dormant or abandoned. The leader is Memos with 62k stars against a category median of 5.9k — roughly 11x the typical project. Saturation score 49/100: Contested. Several maintained alternatives exist, but no one owns the category.
Winnable, but differentiation is not optional. Pick one underserved segment and be visibly better for it rather than competing feature-for-feature with a free tool.
The practical test in this category: Memos is the reference implementation at 62k stars, and 14 of 20 projects are still shipping. A buyer evaluating you will find at least one maintained free option, so your pricing and positioning have to answer "why not self-host Memos?" in the first minute.
Note-taking & Editors
Knowledge base that works with a SQLite db file.
Alternative to Evernote, Onenote, Roam Research, Note-taking/ Knowledge management, Note-taking / Personal Knowledge Management
Note taking application with markdown editor and encryption support for mobile and desktop platforms. Runs client-side and syncs through a self hosted Nextcloud instance or similar (alternative to Eve
Note-taking & Editors
Cross-platform hierarchical note taking application with focus on building large personal knowledge bases (fork of Trilium Notes).
Note-taking & Editors
Web-based collaborative LaTeX editor.
Note-taking & Editors
Collaborative note taking, wiki and documentation platform that scales.
Note-taking & Editors
A personal note tool with AI features.
Note-taking & Editors
Diagram software for making flowcharts, process diagrams, org charts, UML, ER and network diagrams.
Note-taking & Editors
Realtime collaborative markdown notes on all platforms, formerly known as CodiMD and HackMD CE.
Note-taking & Editors
Simple and private notes app. Protect your privacy while getting more done. That's Standard Notes.
Note-taking & Editors
Note-taking application optimized for people with a hacker mindset.
Note-taking & Editors
Realtime collaborative notebook app based on Markdown that supports running Elixir code snippets, TeX and Mermaid Diagrams. Easily deployed using Docker or Elixir.
Note-taking & Editors
Database-less note-taking web app that utilises a flat folder of markdown files for storage.
Note-taking & Editors
Lightweight but powerful alternative for managing your personal, file based, notes and checklists.
Note-taking & Editors
Lightweight distraction-free text editor, in the browser (Markdown and LaTeX supported). No lag when writing.
Note-taking & Editors
Markdown note-taking web application designed for simplicity.
Note-taking & Editors
Minimal web-based Markdown notes app.
Note-taking & Editors
Encrypted diary Web application to save your personal memories of each day. Includes a search function and encrypted file upload.
Note-taking & Editors
Modern note taking application for the cloud, utilizing the best features of progressive web apps technology.
Note-taking & Editors
Markdown notes taking app with live preview, document encryption, multi-user support, multi-organization capabilities and more.
Note-taking & Editors
Totally private personal database and note taking app.
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.
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.
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.
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.
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.
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.
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.
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.
IdeaProof scores your idea against real competitors, market size and 1,000+ documented startup failures in about two minutes.
Validate your idea free