Viewer-first
Stay in context from the README to the Office handoff
Use the file tree and tabs to move through Markdown, PDF, Word, Excel, and PowerPoint files in the same workspace.
Product Site for Developers
One native workspace for Markdown, PDF, and Office documents.
A faster desktop reading experience for technical material from Markdown to PDF and Office documents.
Open local files or direct HTTP(S) URLs in tabs. Read Markdown and HTML, move through PDF and Word pages, PowerPoint slides, and Excel sheets without switching apps.
- 01
Markdown / HTML / PDF / Office
- 02
Page, slide, and sheet controls
- 03
macOS / Windows / Linux
Product Experience
Keep READMEs, PDFs, and Office documents in the same tab workflow
Bring Markdown, HTML, PDF, DOCX, XLSX, PPTX, and technical diagrams into one workspace so document review stays in context.
positioning
Start with what you need
Choose the page that matches your goal so you can quickly understand whether KatanA fits.
fit
Built for technical workflows across document formats
KatanA is a viewer-first workspace for teams that compare Markdown, PDFs, and Office files, without the overhead of a general knowledge base or IDE.
AI-Assisted
Fast preview before passing to AI
Verify source and preview side-by-side to smoothly check specifications and documents before including them in AI prompts.
Native
Comfortable reading even with diagrams and long texts
Native performance powered by Rust and egui maintains a responsive feel even for technical documents heavily using Mermaid, including ZenUML, and PlantUML.
positioning
Fast positioning in one glance
KatanA
Best for technical docs, mixed diagrams, and workspace review.
Viewer-first desktop flow for README, ADR, specs, and release notes.
Typora
Best for single-document writing and lightweight editing.
Strong editor feel, but less workspace-aware for doc sets.
Obsidian
Best for knowledge-base and plugin-heavy personal systems.
Excellent graph/wiki workflows; less focused on spec review work.
Who this is for
- Engineers reviewing ADRs and architecture specs daily.
- Teams reading Mermaid (including ZenUML) / PlantUML / Draw.io mixed documentation.
- AI-assisted development workflows that depend on clean spec reading.
Behind KatanA
A product built to bridge the gap between lightweight Markdown tools and documentation-heavy engineering work.
- In Spec-Driven Development, screen readability before editing is crucial.
- In the age of AI agents, specifications and ADRs are becoming even more important.
- General-purpose note apps and heavyweight editors are too much overhead when you only need to review documents.
Roadmap: The Evolving Workspace
KatanA is evolving from a stable viewer into an essential document authoring and verification tool for the AI era.
- Enhanced Markdown writing and optimized image asset management (v0.22.0)
- Auto-fix support for Linter powered by local LLM (v0.23.0)
- AI-driven document generation and multi-language translation overlay (v0.24.0 - v0.25.0)
- Refined desktop experience toward the v1.0.0 milestone