BusyMark

Markdown, Writerside, and Nextcloud Notes editor for Linux.

Features

• Markdown editing — Source, Editor, Reading, and Split views with formatting tools, syntax highlighting, code folding, tables, images, links, code blocks, callouts, collapsible content, and document diagnostics.
• Writerside projects — Open and create Writerside-compatible projects; edit Markdown and XML topics; manage instances, tables of contents, reusable TOC libraries, and project structure.
• Nextcloud Notes — Connect to a Nextcloud server, create and edit notes offline, synchronize changes, search and filter notes, manage categories and favorites, and work with attachments.
• Navigation and search — Files, Topics, and Outline views, tabbed documents, command palette, keyboard shortcuts, document search and replace, reviewed replacement across local workspaces, and Markdown TOC generation.
• Technical documentation — Local rendering of Mermaid, PlantUML, D2, fenced OpenAPI specifications, and MathJax mathematical expressions.
• PDF and HTML publishing — Export Markdown documents and Writerside instances to configurable PDF or portable offline HTML, with controls for layout, typography, tables of contents, heading numbering, and HTML styling.
• Git integration for local workspaces — Review changes and diffs, stage and unstage files, commit, create and switch branches, fetch, pull, push, inspect file and project history, compare historical versions, and restore earlier file versions.
• Clipboard and Local History — Reuse source, rich-text, and image fragments during the current session; compare and restore persistent on-device document revisions independently of Git.
• AI-assisted editing — Optional Ollama, OpenAI, and Gemini integration with explicit edit scope and shared context, proposal review before changes are applied, and AI-assisted Git commit-message drafting.
• Workspace reliability — Detect files changed outside BusyMark, recover unsaved documents, restore previous workspace sessions, manage remote-image permissions, and protect Git operations behind workspace trust.

Installation

Install BusyMark from the Snap Store:

sudo snap install busymark --beta

The Snap uses strict confinement. See Snap confinement for filesystem and Git-integration details.

Run from source

BusyMark currently uses Flutter 3.47.5. Install the Linux packages required by Flutter and BusyMark's CMake configuration:

sudo apt-get install -y \
  clang \
  cmake \
  curl \
  fonts-noto-core \
  fonts-noto-mono \
  libgtk-3-dev \
  libhandy-1-dev \
  libsecret-1-dev \
  libwebkit2gtk-4.1-dev \
  ninja-build \
  pkg-config \
  xz-utils

Node.js 22 or newer with npm is also required to build the bundled web components.

Prepare and run the application:

flutter doctor
flutter pub get
flutter run -d linux

Pass a Markdown file or documentation directory after -- to open it at startup:

flutter run -d linux -- /absolute/path/to/document.md
flutter run -d linux -- /absolute/path/to/documentation

Build and run the standard checks with:

flutter build linux
flutter analyze
flutter test

The build assembles BusyMark's runtime components. Packaged users do not need separate Typst, Java, Node.js, or Chromium installations.

The CI workflow installs additional packages for headless X11/Wayland, browser, PDF, and sandbox verification. Those packages are not required for an ordinary local build; see the Linux workflow when reproducing release verification.

Snap release and security builds

Release, security-refresh, and packaging-change artifacts must be built from the current snap/snapcraft.yaml in a clean Ubuntu 24.04 amd64 Snapcraft build environment. The authoritative build sequence is:

snapcraft --version
snapcraft expand-extensions
snapcraft clean
snapcraft
sha256sum ./busymark_*.snap

Inspect and test the exact file emitted by the final snapcraft command. A failed build must not fall back to an older .snap. The snap job in the Linux workflow follows this route, installs that selected artifact, and runs the strict-confinement smoke checks.

tools/build_install_snap_local.sh is intentionally different: it replaces the Flutter payload in an installed Snap scaffold for quick development and may retain that scaffold's Ubuntu libraries and bundled tools. Even with --no-install, its output is not a dependency refresh and must not be used for a release, a security update, or validation of stage-packages changes.

Screenshots

Split view with Markdown source and rendered document.	Editor view with formatting tools and document navigation.
Reading view for rendered documentation.	Keyboard shortcuts reference.
Mermaid and PlantUML diagrams rendered directly in the document.	D2 diagram rendering.
OpenAPI documentation rendering.	Writerside project and table-of-contents editing.

Documentation

The documentation index lists user guides and the separate developer notes.

Markdown and Writerside

BusyMark opens Markdown files using .md and .markdown extensions and can work with ordinary documentation folders.

Writerside-compatible projects are recognized through writerside.cfg and the older project.ihp format. BusyMark supports Markdown and XML topics, Writerside instances, tables of contents, reusable content, project configuration, and other commonly used Writerside documentation features.

More information:

• Writerside support and limitations
• Writerside instances
• Writerside videos
• Admonitions
• Collapsible elements

Nextcloud Notes

BusyMark can open a Nextcloud Notes workspace alongside its local Markdown and Writerside workflows. Notes stay associated with your Nextcloud account rather than a folder on your computer.

Connect your account

1. Ensure the Notes app is enabled on your Nextcloud server.
2. On BusyMark’s welcome screen, choose Nextcloud Notes. You can also open Settings → Nextcloud Notes.
3. Enter the full HTTPS address of your Nextcloud server and click Connect.
4. Complete authorization in your default web browser. BusyMark verifies Notes compatibility and opens the note workspace.

Once connected, select Nextcloud Notes on the welcome screen to reopen the workspace. Use Settings → Nextcloud Notes to open it, reconnect, or disconnect the account. One Nextcloud account can be connected at a time.

Work with notes

• Create and edit: Create notes from the Notes sidebar and edit them using the normal Markdown editor. Use each note’s menu to change its title, category, or favorite status, save a separate local copy, or delete the note.
• Find and organize: Search notes by title, content, or category; filter by favorites or category; and see synchronization status in the note list and editor.
• Work offline: Edits and new notes are saved to local storage before they are synchronized. Pending changes can survive an application restart. Synchronization runs when a connection is available; the sidebar’s Refresh control requests another pass.
• Review conflicts: If a note changes on the server while you have local edits, BusyMark preserves the competing versions for review instead of silently overwriting one. The comparison workflow supports choosing a version, merging changes, or recovering content as a separate note. Ambiguous note-creation results also require explicit review.
• Use attachments: Add files to notes, view supported images and media, and include managed resources when exporting Markdown or HTML. PDF export includes supported images but does not embed arbitrary file attachments. New uploads are limited to 100 MiB per file.
• Export or recover: Export individual notes to PDF or offline HTML, use Save As to create an independent local Markdown copy, and restore earlier content through Local History.

Requirements and limitations

• BusyMark requires a server advertising Nextcloud Notes API 1.4 or later in API major version 1. Notes 6.0.x and 6.1.x are supported baselines. Deleting attachments requires Notes 6.1.0 or newer.
• Connections require HTTPS and certificates trusted by the operating system. Authentication uses Nextcloud’s browser-based Login Flow; the resulting app password is stored in the Linux keyring (libsecret), not in the notes database.

Search and replace

BusyMark supports active-document replacement and reviewed workspace-wide replacement for local workspaces. Nextcloud Notes supports replacement within individual notes, but not workspace-wide replacement. See Search and replace for search options, scope, preview behavior, and stale-result handling.

Diagrams and mathematics

BusyMark renders Mermaid, PlantUML, D2, and fenced OpenAPI content locally. Mathematical expressions are rendered with the bundled MathJax environment.

See:

• Offline visualizations
• Mathematical expressions

Export

BusyMark can export the current Markdown document (including a Nextcloud note) or a Writerside instance to PDF and portable offline HTML.

PDF export supports configurable paper size, orientation, margins, typography, headers and footers, page numbering, table of contents, and heading numbering.

See:

• PDF export settings
• Writerside PDF export
• HTML export

AI editing

AI-assisted editing is optional and disabled by default.

BusyMark supports Ollama, OpenAI, and Google Gemini. Proposed edits are presented for review before changes are applied.

See AI editing for configuration, privacy, provider behavior, and security information.

History and recovery

See Clipboard History and Local History for collection scope, limits, retention, restoration, exclusions, and how these tools differ from undo, crash recovery, and Git. Implementation and verification details are in the history implementation notes.

Contributing

Issues and focused pull requests are welcome.

Changes should remain consistent with BusyMark's scope as a Linux desktop editor for Markdown, Writerside documentation, and Nextcloud Notes.

License

BusyMark is licensed under the Apache License 2.0. See LICENSE.

Licenses and notices for bundled third-party components are distributed with the application.