# vDesign vs Pencil

> Pencil (pen.dev) is an agentic canvas for software, in your IDE and on the desktop, with .pen JSON files in git. vDesign is an agentic canvas for anything people look at, in the browser and on the desktop, with a text format built for models.

## In short

Pencil, now pen.dev, is an agentic design canvas for building software. It runs as a
desktop app on macOS, Windows and Linux, as an extension in VS Code and Cursor, and as a CLI.
Designs are `.pen` files, a JSON format kept in git beside your code. Agents connect over MCP
or through your own AI subscription or key, it imports Figma, and it exports HTML with CSS or
Tailwind, and images and PDF.

vDesign is an agentic design canvas for anything people look at, in the browser or on Mac and
Windows. Designs are `.vd` files: line-based text written for a model to read and patch
directly. The VS Code extension previews them; the app is where they are made.

## Where each one wins

**Choose Pencil** for app and web UI designed next to the code: in your IDE, on Linux, with
Figma import and code export.

**Choose vDesign** for print, marketing, decks, brand and video as well as web pages; for
working in the browser with nothing to install; and for assistants like Claude and ChatGPT
that connect with one URL.

## Side by side

| | vDesign | Pencil (pen.dev) |
| --- | --- | --- |
| The document | `.vd`, line-based text, patched directly by models | `.pen`, JSON, changed through its tools |
| Best at | Print, marketing, slides, brand, video, one-page sites | App and web UI, design-to-code |
| Where it runs | Browser, Mac, Windows | Mac, Windows, Linux, VS Code and Cursor, CLI |
| Agent access | Remote MCP URL for Claude and ChatGPT, local MCP, vDesign AI on your own key | MCP, your own subscription or key |
| In your editor | VS Code, Cursor and github.dev preview, ```vd fences in Markdown | Full editor as an extension |
| Imports | Your brand from its site or files | Figma, web pages |
| Exports | PNG, JPEG, WebP, SVG, PDF, Illustrator, HTML, PowerPoint, GIF, MP4 | HTML with CSS or Tailwind, PNG, JPEG, WebP, PDF |

## Questions

### Both keep designs as files in git. What is different about .vd?

A .pen file is JSON, and pen.dev asks agents to change it through its app, CLI or MCP tools rather than editing it directly. A .vd file is line-based text written for a model to read and patch directly, one line per element, with geometry kept as relationships.

### Does vDesign run on Linux?

The web app does, in any modern browser; Chrome and Edge save back to the same file. There is no Linux desktop build yet.

## Sources

Facts about other products checked on 2026-10-28.

- [pen.dev FAQ](https://pen.dev/faq)
- [pen.dev llms.txt](https://pen.dev/llms.txt)