pscat

PostScript for precision and imagination.
_{The logo is drawn by pscat from its PostScript source.}

pscat is a modern PostScript interpreter written in Rust for reliable document rendering and creative graphics. It renders PostScript and EPS to PNG, SVG and PDF from the command line, as an embeddable Rust library, in the browser via WebAssembly, or through MCP for AI agents.

• Documents: letters, certificates, invitations and posters from page templates, charts and plots for papers, typewritten memos, and multi-page PDFs.
• Art: generative patterns, watercolor and oil paint, printmaking, handwriting, chalkboards and display type.

pscat aims to replace Ghostscript for most PostScript work, and uses Ghostscript as its correctness reference: test expectations are pinned against Ghostscript's output. It can also show a program drawing, stroke by stroke, in a live window or in a browser tab.

_{Both drawn by pscat: a certificate from the page templates, and Evening Stream, painted with the paint library.}

pscatlabs.github.io/pscat has the docs, the full gallery, a specimen of every font, and a live playground that runs the interpreter in your browser, no install.

Install

cargo install pscat          # pscat and pscat-mcp, from crates.io
pscat fonts install          # optional: the full font catalog, as font packs
npm install pscat            # from 0.6.2: the wasm renderer for browsers and Node

Or download a ready-built binary for macOS, Linux or Windows from the releases page (no Rust needed). Getting started has the details. Then:

pscat --png out.png some_file.ps

Quick start from a checkout

You need a stable Rust toolchain.

cargo run -- --page 500x500 examples/sierpinski.ps   # watch it draw, live
cargo run -- --png out.png examples/sierpinski.ps    # render to a PNG instead
cargo run -- -i                                      # REPL + window: type PostScript, watch it draw

A taste of the REPL:

PS> 40 2 add =
42
PS> mark 1 2 3
PS<4> pstack
3
2
1
-mark-

To try it with nothing installed, open the playground. New to PostScript? Start with Learn PostScript. More sample programs live in examples/, and finished pieces in gallery/.

LaTeX on a chalkboard

pscat chalk writes a formula on a chalkboard from plain LaTeX, with no PostScript. The same LaTeX and seed give the same picture:

pscat chalk 'x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}' -o quadratic.png

More boards, each with its command, are on the site; the options and the supported LaTeX are in the dry-media guide. MCP clients get the same board from the chalkboard_math tool.

Guides

Everything else is in docs/guides/:

• Getting started: build, install, command-line flags, output formats
• pscat in the browser and for AI agents
• Fonts and handwriting
• artkit: the generative-art toolkit, and style packs and page templates
• Painting and the landscape cookbook
• Printmaking and etching and dry media
• Lettering, headlines and apparel
• Charts and plots

For AI agents

pscat works well from a coding agent. The skills in plugin/skills/ (pscat, psart, psviz) are plain Markdown any agent can read, and pscat-mcp is an MCP server with ten tools. In Claude Code, both come as one plugin: /plugin install pscat --marketplace PSCatLabs/pscat (after installing pscat; see plugin/README.md). In Codex: codex plugin marketplace add PSCatLabs/pscat, then codex plugin add pscat@pscat. See the agents guide. Any other MCP client can run pscat mcp (the same server as pscat-mcp), and pscat is listed in the MCP Registry from 0.6.3:

• MCP Registry name: mcp-name: io.github.PSCatLabs/pscat

Contributing

Start with CONTRIBUTING.md (including how contributions are licensed), then AGENTS.md for conventions and SDLC.md for how changes land. Report security problems as SECURITY.md describes, and see docs/STABILITY.md for what stays stable between releases. docs/dev/HANDOFF.md orients you in the code, docs/dev/ARCHITECTURE.md explains the design, and docs/dev/ has the contributor notes, such as how to preview the website. docs/archive/ holds the project's history, including the original stage-by-stage status log.

Why

I used to write raw PostScript by hand in college and send it straight to a LaserWriter. This is a from-scratch Rust interpreter built to relive that — watching a hand-written recursive PostScript program draw itself, live, without depending on a decades-old C codebase to do it.

Licence

pscat's code is dual-licensed under MIT or Apache-2.0, at your option. The package also embeds font data: the Liberation faces, the URW Symbol and ZapfDingbats faces and the Courier Prime-derived typewriter outlines, under the SIL Open Font License 1.1, and the TeX Gyre faces, under the GUST Font License (LPPL-1.3c). That's why Cargo.toml says (MIT OR Apache-2.0) AND OFL-1.1 AND LPPL-1.3c. The font terms cover only the embedded font data, not pscat's code.

The fonts in fonts/catalog/ keep their own upstream licences. The original gallery, example and shirt art is dedicated to the public domain under CC0-1.0, with a few exceptions. CC0 grants no rights in the pscat name or logo. THIRD_PARTY_NOTICES.md lists what is under which terms.

SDLC

See SDLC.md for how this repo's development lifecycle works (issue → branch → PR → review → merge → cleanup) and the branch-protection/merge policy currently enforced on GitHub — generated and kept in sync by the sdlcify skill.