Licence

JETCARP’s own code, data and documentation

JETCARP is dual-licensed under the Unlicense and the MIT licence: you may use its own code and data under either, at your option. The aim is public-domain research software. The Unlicense dedicates the work to the public domain; the MIT licence is offered as a fallback for places that do not recognise a public-domain dedication. The same dual licence covers this documentation: its text, its figures and the scenes that make them. Short passages it quotes from other works, with their sources cited, remain their authors’. The short explanation is in COPYING.

Contributions are accepted under the same dual licence (see Contributing).

Data from JETCARP’s searches

Packs, the format for sharing catalogues and search results, come in a later release. Packs made by JETCARP’s own searches will be released under the Creative Commons CC0 1.0 public-domain dedication (CC0-1.0). People who make packs of their own can choose another open licence for them.

Third-party work

A few files in JETCARP contain or are derived from other people’s work. Each keeps its own licence, all of which allow redistribution under JETCARP’s terms, and their notices must stay with any copy or derivative of those files. The full notices and licence texts are in THIRD_PARTY_NOTICES.md; in summary:

The Spectre visualizer. Kaplan’s spectre.js was published without a licence. Asked whether JETCARP could use it, Kaplan made it available to JETCARP under BSD 3-Clause, the same terms as hatviz, by email to Jimmie Rodgers on 10 November 2026.

The k-uniform data. JETCARP converted the data: tools/gen_kuniform.py rebuilds each tiling’s exact geometry, translation lattice, symmetry group and vertex orbits from the source and writes them in JETCARP’s own format. The source file is kept unchanged in the repository. Work that uses these tilings should credit the catalogue and its encoding (see Citing JETCARP).

Methods written without copying code

These carry no licence obligation, but the work they come from is credited here and on the pages that describe them:

• The evolutionary glider search, James Edmond’s method, written from Edmond’s paper (arXiv:2609.22579) and a reading of Edmond’s repository, apart from the two functions listed above (see Search methods).
• The Spectre glider rule (SpectreGlider), Edmond’s published rule (Table 7 of Edmond’s paper).
• Von Neumann’s 29-state automaton, written from von Neumann’s Theory of Self-Reproducing Automata, edited by A. W. Burks (1966), with no text, figures, rule files or patterns from other programs.
• The WebP lossless encoder (crates/jetcarp-core/src/media/vp8l.rs), written from the WebP Lossless Bitstream Specification (RFC 9649), with no libwebp code.

JETCARP contains no code, rule files or pattern files from Golly. The descriptions of named rules are written in JETCARP’s own words; the names, notations and credits come from LifeWiki and the other sources listed in the named rule catalogue.

Compiled releases

Compiled releases are built from Rust libraries under permissive licences (MIT, Apache-2.0, BSD, Zlib, ISC, Unicode-3.0 and others); two are under MPL-2.0 and are used unmodified. Their notices ship with each release in THIRD_PARTY_LICENSES.html, generated by cargo-about. Releases also bundle the SQLite library, which is in the public domain, the Zstandard compression library (BSD 3-Clause, © Meta Platforms, Inc. and affiliates), and the user-interface fonts that come with egui: Ubuntu Light (Ubuntu Font Licence 1.0), Hack (MIT, with the Bitstream Vera licence), Noto Emoji (SIL Open Font Licence 1.1) and emoji-icon-font (MIT).