Stop opening Word files one by one.
Search your team's documentation, right on the shared drive you already have.
Download · Getting started · Why Cairn · Docs
Cairn is a documentation app for teams that keep their files on a shared network drive. Point it at a folder, and everyone on the team can read, search, and write pages in their normal web browser: no server to run, no accounts to manage, and no cloud service. The pages are ordinary Markdown files in your folder, so your documentation stays yours.
Many companies still keep their documentation on a shared drive as a tree of Word files. It works, until you need an answer in a hurry:
- Finding something is slow. To learn which file mentions "VPN" or "month-end close", you open files one by one, and each large Word file takes a moment to load.
- Searching doesn't reach inside the files. The drive can find a file name, but looking for the words in your documents usually means opening Word.
- Editing gets in each other's way. Someone has the file open, someone else saves a copy called
final_v2, and nobody is sure which is current. - Not everyone is comfortable with the tools. The people who most need the answer are often the least likely to fight with software to find it.
Cairn keeps the shared drive you already have and puts a simple, searchable handbook on top of it:
| On a shared drive of Word files | With Cairn |
|---|---|
| Open files one at a time to find a keyword | Type a word in the search box and see every page that mentions it |
| Wait for each document to open | Pages open right in your browser, with a table of contents |
| "The file is locked for editing by someone" | One person edits a page at a time, and others can keep reading it, with their name shown |
Policy_final_v2_REAL.docx |
Every page keeps its earlier versions, and you can bring one back |
| Broken links when someone renames or moves a file | Rename or move a page and the links to it are updated for you |
| Documents tied to one program | Plain .md files and pictures that any text editor can open |
You don't need to be technical to use it. Every button has words on it, you can format a page without knowing Markdown, and the text can be made larger in Settings.
- Pick a folder. Choose a folder on your shared drive (or create a new one). That folder is your documentation.
- Everyone runs Cairn on their own computer. It opens the documentation in their usual browser. Nothing is installed on the drive and nothing leaves it.
- Read, search, and write. Cairn coordinates people through small files in the folder itself, using the permissions the drive already has.
If you stop using Cairn, your documentation is still just a folder of .md files and pictures. The only thing Cairn fetches from the internet is news of a new version of itself, once a day (you can turn that off).
Moving from Word? Cairn doesn't import
.docxfiles automatically. Start new pages in Cairn and bring over the ones people use most; the old files can stay on the drive for as long as you like.
- Every button has words on it. Nothing is hidden behind icons, hamburger menus, or keyboard shortcuts.
- You can write and format a page without knowing Markdown: toolbar buttons such as Heading, Bullet list, Link…, and Insert picture… do it for you, and a live preview shows how the page will look.
- Text can be made larger in Settings, and the layout adapts to any window size, from a full desktop screen to half a screen or a phone. There are Light, Dark, and High contrast color schemes.
- Messages use plain words and always say what to do next.
- Read and search pages, with a table of contents, owner, status, and last-reviewed date for each page.
- Edit safely. One person edits a page at a time. Others see “Being edited by Alex since 2:30 PM” and can keep reading.
- Never lose work. Unsaved changes are kept privately on your own computer every few seconds. If someone changed the page while you were writing, Cairn shows both versions instead of overwriting either one.
- Pictures by button, paste, or drag and drop. They are stored next to the page in a normal folder.
- Earlier versions of every page are kept and can be restored.
- Rename, move, and delete pages and folders. Links between pages are updated for you, and anything deleted can be brought back from Recently deleted.
- Team templates for pages you write often, kept with each documentation folder, with fields such as the title and today's date filled in for you.
- Download a page as PDF or Markdown, or a whole folder or all documentation as a .zip. PDFs are made on your own computer.
- Your timezone. Times are stored in one standard form and shown in each person's timezone, marked like “2:30 PM GMT+8”.
- Updates itself. Cairn tells you when a new version is out and installs it with one click, after checking it's signed by Cairn's makers. You can always go back to the version before.
-
Download Cairn from the Releases page:
- Windows:
cairn-…-setup.exe. Run it; no administrator password is needed. - Mac:
cairn-…-macos-universal.zip. Open it and drag Cairn to your Applications folder. The first time, choose Open Anyway in System Settings → Privacy & Security (how). - Linux:
cairn-…-linux-x86_64.AppImage. Double-click it, or run it from a terminal.
Cairn is installed just for you and can update itself. (Or build it yourself: see Building Cairn.)
- Windows:
-
Start Cairn. A small window opens (a Terminal window on a Mac or Linux) and your browser shows Cairn.
-
Choose Create a new documentation folder (or Open a documentation folder we already use).
-
Choose New page, give it a title, and start writing. Choose Publish changes when you're done.
Keep the small Cairn window open while you use Cairn. Closing it stops Cairn.
The full walkthrough is in docs/getting-started.md.
The home screen: the page tree, search, folders, and recently changed pages with who edited them.
A page: its place in the tree, its owner, status, and who last edited it, with "On this page" beside it.
Visual editing: write on the page as it will look. Markdown shortcuts such as ## and - format as you type.
Or show the formatting codes, with a live preview beside them.
More screenshots: templates, downloads, and timezones
Team templates, kept with each documentation folder.
Download a page as a PDF or as Markdown.
Choose the timezone times are shown in.
The screenshots use made-up sample content.
| Guide | What it covers |
|---|---|
| Getting started | Installing, opening or creating a documentation folder, your first page |
| Writing pages | Formatting, pictures, unsaved changes, publishing, earlier versions |
| Architecture | How the local program, the browser, and the files fit together |
| Storage and concurrency | The marker file, edit locks, time-outs, conflicts, recovery, and filesystem limits |
| Configuration | Settings and the workspace file format |
| Troubleshooting | Shared-folder access, failed publishing, abandoned locks, restoring unsaved changes |
| Two-computer test checklist | Manual checks for network-share behavior |
| Building Cairn | Step by step: from a new computer to your own build of Cairn |
| Contributing | Running, testing, and working on the code |
| Changelog | What changed in each release |
Found a problem, have an idea, or got stuck? Open an issue and pick the kind that fits. Plain words are fine; please leave out anything private from your documentation. Security problems go privately instead.
- Systems. Cairn runs on Windows 10/11 (x64), macOS 11 or newer (Apple silicon and Intel), and 64-bit Linux (x86_64). On other systems it can be built from source, but it doesn't update itself there.
- Edit locks need suitable storage. Locks and safe replacement rely on exclusive file creation and atomic rename, which local disks (NTFS, APFS, ext4) and SMB2/SMB3 network shares provide. Cloud-synced folders (OneDrive, Dropbox, Google Drive) and some network storage do not. Cairn checks the storage when a folder is opened and warns when editing by several people at once is not safe. See storage and concurrency.
- Cairn only knows about Cairn. If someone edits a
.mdfile directly in another program, Cairn can't show them as the editor. It does notice the change when someone tries to publish, and shows a comparison instead of overwriting. - Access control is the filesystem's job. Cairn hides editing where you can't write, but the real protection is the shared folder's own permissions.
- Pictures: PNG, JPEG, WebP, and GIF only. SVG is not accepted.
- No viewer presence. Cairn does not show who is currently reading a page.
- Unsigned download. Cairn isn't signed with a paid certificate, so Windows SmartScreen may warn the first time you run it (choose More info → Run anyway), and a Mac asks you to allow it once in System Settings → Privacy & Security. Each download has a
.sha256next to it to check it against.
MIT. The bundled Inter font is under the SIL Open Font License (assets/fonts/Inter-LICENSE.txt).