Skip to content

Licensing and Acknowledgements

Pulp License

Pulp is released under the MIT License. You can use it for any purpose — commercial, personal, educational — with no royalties, revenue thresholds, or copyleft obligations. See LICENSE.md for the full text.

Third-Party Dependencies

Pulp builds on excellent open-source software. Every dependency that Pulp bundles, fetches automatically, or redistributes is compatible with MIT licensing — there is no copyleft in the shipped dependency chain.

Tables are sorted alphabetically (case-insensitive) by name. Entries here must stay in sync with DEPENDENCIES.md, NOTICE.md, and tools/deps/manifest.json (the machine-readable source of truth).

Core Dependencies (Always Used)

Name License Purpose Link
Catch2 BSL-1.0 Unit testing framework github.com/catchorg/Catch2
CHOC ISC JS engine, MIDI utilities, audio file I/O, WebView, networking github.com/Tracktion/choc
cpp-httplib MIT HTTP client (GET/POST/download) used by pulp-runtime github.com/yhirose/cpp-httplib
dr_libs Public domain (Unlicense) / MIT-0 FLAC, MP3, WAV decode (dr_flac, dr_mp3, dr_wav) github.com/mackron/dr_libs
Highway Apache-2.0 Portable SIMD abstraction (SSE/NEON/AVX) github.com/google/highway
Mbed TLS Apache-2.0 (dual-licensed; Pulp uses the Apache-2.0 option) Cryptographic primitives (SHA-256, RSA, AES) github.com/Mbed-TLS/mbedtls
miniz MIT ZIP/GZIP compression github.com/richgel999/miniz
msdfgen MIT Reserved for multi-channel SDF glyph generation github.com/Chlumsky/msdfgen
nanosvg zlib SVG parsing and rasterization github.com/memononen/nanosvg
pugixml MIT XML parsing and generation github.com/zeux/pugixml
SheenBidi Apache-2.0 Unicode Bidirectional Algorithm engine for Arabic / Hebrew / mixed-direction text in core/canvas::BidiAnalyzer (independent of system ICU) github.com/Tehreer/SheenBidi
TweetNaCl Public domain Ed25519 sign/verify per RFC 8032 — Sparkle appcast signatures and signed node/package metadata tweetnacl.cr.yp.to
yaml-cpp MIT YAML frontmatter parser for the DESIGN.md import pipeline (gated to --from designmd) github.com/jbeder/yaml-cpp
Yoga MIT Layout engine for Flexbox/Grid-style native UI github.com/facebook/yoga

Import Tooling Dependencies

These packages are npm-installed for design-import tooling and validation. They are not bundled into Pulp's C++ runtime.

Name License Purpose Link
Babel parser MIT JSX/TSX source-contract extraction for tools/import-design/jsx-runtime/jsx-contract-audit.mjs github.com/babel/babel/tree/main/packages/babel-parser
css-tree MIT CSS value parsing and lexer validation for JSX source-contract extraction github.com/csstree/csstree

Design Formats and Test Fixtures

Pulp adopts Google's DESIGN.md format as a first-class import source (pulp import-design --from designmd). The format specification is reimplemented in C++ (no upstream code vendored); the YAML frontmatter is parsed with yaml-cpp (see Core Dependencies above). One example file from upstream examples/paws-and-paths/ is redistributed verbatim as the test fixture at test/fixtures/imports/designmd/alpha/DESIGN.md.

Name License Purpose Link
DESIGN.md format spec + paws-and-paths fixture Apache-2.0 Design-system interchange format consumed by pulp import-design --from designmd; one upstream example file redistributed verbatim as a Pulp test fixture. Pinned at tag 0.1.1. github.com/google-labs-code/design.md @ 0.1.1
Khronos Box Textured fixture LicenseRef-CC-BY-TM + LicenseRef-LegalMark-Cesium Official glTF Sample Assets BoxTextured.glb redistributed as a Scene3D native loader/render test fixture at test/fixtures/scene3d/BoxTextured/BoxTextured.glb. github.com/KhronosGroup/glTF-Sample-Assets/Models/BoxTextured

Embedded Fonts

Embedded at build time for deterministic text rendering. Both fonts are redistributed under the SIL OFL 1.1, which explicitly permits bundling in software.

Name License Purpose Link
Inter SIL OFL 1.1 Embedded UI font (Inter-Regular.ttf, version 4.001;git-9221beed3) github.com/rsms/inter
JetBrains Mono SIL OFL 1.1 Embedded monospace font (JetBrainsMono-Regular.ttf, version 2.304) github.com/JetBrains/JetBrainsMono
Noto Color Emoji SIL OFL 1.1 Embedded cross-platform color-emoji typeface (NotoColorEmoji.ttf, COLRv1, noto-emoji main @ 2026-05-17). Gated by PULP_BUNDLE_NOTO_COLOR_EMOJI (defaults ON for Linux/Android/headless, OFF for macOS/Windows where the platform color-emoji typeface is preferred). github.com/googlefonts/noto-emoji

Plugin Format SDKs

Name License Purpose Link
AudioUnitSDK Apache-2.0 AU v2 plugin format adapter github.com/apple/AudioUnitSDK
CLAP MIT CLAP plugin format headers github.com/free-audio/clap
LV2 ISC LV2 plugin format headers github.com/lv2/lv2
VST3 SDK MIT VST3 plugin format (pluginterfaces + base) github.com/steinbergmedia/vst3sdk

Platform-Specific Dependencies

Name License Purpose Link
Oboe Apache-2.0 Android audio backend (AAudio/OpenSL ES abstraction) github.com/google/oboe

System Services & OS-Provided Dependencies

Pulp integrates with a number of operating-system services, libraries, and frameworks to reach native audio, MIDI, Bluetooth, accessibility, windowing, and desktop-integration features. Pulp does not bundle, vendor, fetch, or redistribute any of these — they are provided by the user's operating system or installed by the user, and Pulp reaches them by dynamically linking a system library, dlopen-ing it at runtime, talking to a system service over D-Bus IPC, or invoking a command-line tool as a subprocess. They are therefore not listed in NOTICE.md (which covers code Pulp redistributes), but are recognized here because Pulp uses them.

Name License How Pulp uses it Platform
ALSA (alsa-lib / libasound) LGPL-2.1-or-later Dynamically linked for native audio + MIDI I/O Linux
JACK (libjack; incl. PipeWire's JACK layer) LGPL-2.1-or-later Optional low-latency audio; linked only when present at build time Linux
D-Bus (libdbus-1) AFL-2.1 OR GPL-2.0-or-later Runtime-dlopened desktop IPC transport (portals, accessibility, BlueZ) — no build-time link Linux
BlueZ (org.bluez) GPL-2.0-or-later (daemon), LGPL-2.1-or-later (libraries) Bluetooth-LE MIDI via the org.bluez D-Bus service (IPC only; not linked) Linux
xdg-desktop-portal LGPL-2.1-or-later Native file open/save dialogs via D-Bus (IPC) Linux
AT-SPI2 (at-spi2-core) LGPL-2.1-or-later Accessibility tree exposed over the a11y D-Bus (IPC) Linux
xclip / xsel / wl-clipboard GPL-2.0-or-later / GPL-3.0-or-later Arbitrary-MIME clipboard via subprocess (not linked) Linux
Windows SDK / WinRT (Windows.Devices.Bluetooth, WASAPI, UI Automation, Win32) Microsoft — OS/SDK provided Bluetooth-LE MIDI, audio I/O, accessibility, dialogs, windowing via system APIs (base SDK; no out-of-band package) Windows
Apple system frameworks (CoreAudio, CoreMIDI, CoreBluetooth, Cocoa/UIKit, …) Apple — OS provided Audio/MIDI/Bluetooth/windowing via system frameworks macOS / iOS

Docs Build & Site Assets

The public docs site (generouscorp.com/pulp/) is generated by MkDocs Material. The following Python packages and their bundled CSS/JS/SVG assets are redistributed as part of the generated site.

Name License Purpose Link
Material Design Icons Apache-2.0 Icon set bundled inside mkdocs-material; redistributed as SVG in the generated docs site github.com/Templarian/MaterialDesign
mkdocs BSD-2-Clause Static site generator (transitive via mkdocs-material); theme assets redistributed in the generated docs site github.com/mkdocs/mkdocs
mkdocs-awesome-pages-plugin MIT MkDocs plugin for navigation ordering (build-time) github.com/lukasgeiter/mkdocs-awesome-pages-plugin
mkdocs-git-revision-date-localized-plugin MIT MkDocs plugin for git-revision dates (build-time) github.com/timvink/mkdocs-git-revision-date-localized-plugin
mkdocs-material MIT Material theme — CSS, JS, SVG icons, and search worker redistributed in the generated docs site github.com/squidfunk/mkdocs-material
Pygments BSD-2-Clause Syntax highlighter used by pymdownx.highlight; redistributed as inline HTML/CSS github.com/pygments/pygments
pymdown-extensions MIT Markdown extension bundle used by mkdocs-material (admonitions, tabs, superfences, highlight, emoji) github.com/facelessuser/pymdown-extensions

Optional Vendor SDK Integrations

Some optional integrations depend on separately licensed SDKs that Pulp does not bundle, fetch, export, or redistribute. These SDKs are outside Pulp's MIT dependency chain and are only supported through explicit opt-in local configuration.

Name License Purpose Distribution
AAX SDK Separately licensed by Avid Optional AAX plugin format support Developer obtains it independently and points PULP_AAX_SDK_DIR at an out-of-tree SDK copy
ARA SDK MIT-compatible (Celemony) Optional ARA 2.x integration (pitch correction, spectral editing, clip-aware workflows) Developer obtains it independently (https://github.com/Celemony/ARA_SDK), keeps it out-of-tree, points PULP_ARA_SDK_DIR at it, and sets PULP_ENABLE_ARA=ON. Never bundled.
ASIO SDK Proprietary (Steinberg) Optional ASIO device I/O integration Developer obtains it independently; never bundled or exported by Pulp

Pulp's MIT license does not grant any rights to these vendor SDKs or to any related Avid/PACE tooling. See AAX Setup for the supported local workflow.

GPU and Windowing

Name License Purpose Link
Dawn BSD-3-Clause WebGPU implementation (Metal, D3D12, Vulkan), pinned via Skia chrome/m144 DEPS at 6acf6ef3fe23 dawn.googlesource.com
SDL3 zlib Cross-platform windowing and input github.com/libsdl-org/SDL
Skia BSD-3-Clause 2D GPU rendering engine (Graphite backend), pinned to chrome/m144 @ cd0c5f445516 with bundled HarfBuzz and ICU DEPS revisions locked for deterministic text shaping skia.org
WebGPU-distribution MIT WebGPU C API wrapper for Dawn github.com/eliemichel/WebGPU-distribution

Optional Dependencies

Fetched or installed only when the corresponding CMake option, platform gate, or developer tool is used. Developer-only entries (e.g. the video-proof composer's ffmpeg-static and Remotion) are never bundled into Pulp or shipped in end-user plugins — Pulp commits only its own glue source and the packages are installed on demand via npm.

Name License Purpose Link
DRACO Apache-2.0 Optional glTF mesh decompression; fetched only when PULP_ENABLE_DRACO=ON github.com/google/draco
Emscripten MIT C++ to WebAssembly compiler (for WAMv2/WebCLAP) emscripten.org
fastgltf MIT Optional native no-JS glTF/GLB parser; fetched only when PULP_ENABLE_SCENE3D=ON github.com/spnda/fastgltf
ffmpeg-static Wrapper MIT; bundled FFmpeg binaries GPL/LGPL Developer-only desktop video-proof composer (tools/local-ci); encodes captured frames to MP4 (a system PULP_FFMPEG works too). npm-installed on demand — never bundled or shipped in plugins github.com/eugeneware/ffmpeg-static
node-addon-api MIT Node.js bindings via Node-API github.com/nodejs/node-addon-api
pybind11 BSD-3-Clause Python bindings for HeadlessHost github.com/pybind/pybind11
react MIT Peer dependency of @pulp/react (packages/pulp-react); npm-installed by plugin authors, never bundled into Pulp itself github.com/facebook/react
react-reconciler MIT Reconciler runtime wrapped by @pulp/react to drive pulp::view::WidgetBridge; npm-installed alongside the package github.com/facebook/react
Remotion Remotion License (source-available; free under their tier, paid company license above it) Developer-only desktop video-proof composer (tools/local-ci); turns automation run bundles into short annotated MP4s. npm-installed on demand — never bundled or shipped in plugins. Companies over Remotion's free tier need a license github.com/remotion-dev/remotion
scheduler MIT Cooperative-scheduling runtime pulled in transitively by react-reconciler for @pulp/react; npm-installed github.com/facebook/react
simdjson Apache-2.0 JSON parser used by fastgltf; fetched only when PULP_ENABLE_SCENE3D=ON github.com/simdjson/simdjson
three.js MIT Native WebGPU bridge demos and tests; fetched only when PULP_BUILD_TESTS and PULP_ENABLE_GPU are ON github.com/mrdoob/three.js
V8 BSD-3-Clause Optional JS engine backend, selected with PULP_JS_ENGINE=v8 (default is QuickJS, JSC on Apple). Sealed prebuilt libv8 (bundles ICU/zlib/Abseil internally — see NOTICE.md); fetched per-platform via tools/scripts/fetch_v8_for_release.py. iOS is JSC-only (V8 needs JIT) github.com/danielraffel/v8-builder

Developer-Only Tooling (not shipped)

Building, testing, and reviewing Pulp uses developer-only tools that are never bundled into Pulp or shipped in end-user plugins — installed on demand via npm/pip and used under their own licenses. (The video-proof composer's Remotion and ffmpeg-static are listed under Optional Dependencies above.) Full inventory and boundary live in DEPENDENCIES.md.

Name License Purpose
esbuild MIT Build-time JS/TS bundler for @pulp/react, pulp-import-ir, the Figma plugin, and the Three.js bundle
TypeScript Apache-2.0 Type-checking/build for the TypeScript packages and the Figma plugin
Vitest MIT Unit tests for @pulp/react and pulp-import-ir
json-schema-to-typescript MIT TypeScript type generation for the Figma plugin
fflate MIT Deflate/zip in the developer-only Figma plugin
numpy BSD-3-Clause Motion visual-analysis lane (tools/motion/visual)
Pillow HPND (BSD-style) Image IO for the Motion visual-analysis lane
scikit-image BSD-3-Clause Image metrics for the Motion visual-analysis lane
opencv-python Apache-2.0 (OpenCV); packaging MIT Optional affine estimation for the Motion visual-analysis lane (graceful fallback)

Type-only @types/* and @figma/plugin-typings, and environment-supplied prerequisites — the Rust toolchain (cargo/rustc), yamllint (GPL-3.0), actionlint, and Docker — are likewise developer/CI-only and never shipped.

Standards and Specifications

Pulp implements or builds on these open standards:

Standard Organization Purpose
Audio Unit Apple Plugin format specification
CLAP Clever Audio Plugin format specification
LV2 LV2 Community Plugin format specification
MIDI 2.0 UMP MIDI Association Universal MIDI Packet format
OSC 1.0 CNMAT Open Sound Control messaging
VST3 Steinberg Plugin format specification
WAMv2 Web Audio Modules Web plugin standard
WASI WebAssembly CG System interface for WebAssembly
Web Audio API W3C Browser audio processing
Web MIDI API W3C Browser MIDI access
WebCLAP WebCLAP Portable CLAP plugins via WebAssembly
WebGPU W3C GPU rendering API

Pulp's JS/React UI layer also targets the web-platform standards below. These are implemented as a deliberate, tracked subset (Pulp is Flexbox + Grid only by design — see the layout model); per-property / per-API status lives in the project compatibility matrix, and @pulp/react provides a React-compatible renderer (via react-reconciler) over the same WidgetBridge.

Standard Organization Purpose
CSS Flexible Box Layout Level 1 W3C UI layout — flexbox box model (via Yoga)
CSS Grid Layout Level 1 W3C UI layout — grid (partial; via Yoga)
CSS (visual properties) W3C Box model, color, typography, transform/transition subset applied to the view tree
HTML Canvas 2D Context WHATWG 2D drawing API exposed to JS UIs (backed by Skia / CoreGraphics)
DOM & UI Events WHATWG document / Element / event subset targeted by the JS UI layer
ECMAScript Ecma International (TC39) JavaScript language for scripted UIs (engine-dependent: QuickJS / JSC / V8)
W3C Design Tokens (DTCG) W3C Community Group Design-token interchange format (import / export)
Unicode Bidirectional Algorithm (UAX #9) Unicode Consortium Bidirectional text layout (via SheenBidi)
glTF 2.0 Khronos Group Optional 3D scene/asset format (Scene3D)

Google's DESIGN.md (above) is an import format, not a standard.

Projects That Inspired Pulp

Project License What We Learned
Astral (uv, Ruff, ty) Apache-2.0 / MIT CI/CD security baseline, supply chain hardening, and release process discipline. Pulp adopts several practices from their open-source security post. Already in place: branch protection on main, tag protection on v*, default read-only workflow tokens, immutable release identity via tag protection. In progress: action SHA pinning via Renovate, immutable release artifacts, Sigstore release attestations, zizmor workflow lint in CI.
AudioKit MIT Swift audio patterns, Apple platform integration
ELYSIUM by Julian Behrens Figma Community (design; not redistributed) A real-world plugin UI we used to harden Pulp's Figma design-importer: faithful-vector SVG rendering and crop, knob/shape fidelity (indicator erasure, value-driven fills), and the source-detected native interactive overlays (search, dropdown, < > stepper, tabs). Used only as a private test reference — the design is not vendored, bundled, or shipped in Pulp, and nothing about it is hardcoded; the lessons are generalized. Thanks to Julian Behrens (vst-design.com) for sharing it on the Figma Community.
iPlug2 zlib-like Multi-format adapter architecture, graphics abstraction
MotionEyes MIT Agent-first motion observability shape behind pulp::view::motion: the Trace.value / Trace.geometry / Trace.scrollGeometry DSL, FrameClock-driven change-only sampling with epsilon/precision, the SwiftUI GeometryReader probe pattern, and the Start/End burst framing that lets agents read animation behavior from logs instead of guessing from source. Pulp re-implements all of this from scratch in cross-platform C++20 with Swift, Kotlin (Android), and JS facades — no MotionEyes source code, headers, or fixtures are copied or vendored. We learned the shape; the implementation is independent.
SignalKit MIT Real-time DSP patterns in Swift
signalsmith-clap-cpp MIT WCLAP build pipeline, webview extension patterns
Visage MIT SDF-first rendering, dirty region tracking, shape batching, and a high bar for visual quality in audio plugin interfaces

Discipline

Pulp follows strict rules. Implementation is from specs, SDK documentation, and original design — never from studying proprietary or restrictively-licensed source code. For optional AAX support, that means no Avid SDK files or example sources in the repo and no copied implementation text from the SDK examples. See CLAUDE.md for the full policy.

License Policy

Before adding any bundled dependency to Pulp:

  1. Check the license — must be MIT, BSD, Apache 2.0, ISC, zlib, BSL-1.0, SIL OFL 1.1 (fonts), or public domain
  2. Add to DEPENDENCIES.md — alphabetical order, with version, license, and purpose
  3. Add to NOTICE.md — full license text, alphabetical order
  4. Add to docs/reference/licensing.md — same table row, matching license string
  5. Update tools/deps/manifest.json — machine-readable inventory consumed by tools/deps/audit.py
  6. No copyleft — GPL, LGPL, AGPL, SSPL are not allowed
  7. MPL-2.0 — requires case-by-case review (weak copyleft)
  8. Vendor SDKs stay separate — optional AAX/ASIO-style SDKs must remain developer-supplied, out-of-tree, and excluded from NOTICE.md

Dependency update workflow is tracked in tools/deps/manifest.json and audited by tools/deps/audit.py. Run python3 tools/deps/audit.py --strict before proposing a dependency change; the audit script will also run in CI (tracked alongside the skill-sync and version-bump gates).