# Reference implementations and sources

Inspection date: 2026-07-27.

| Reference                        | Exact revision/version                                                                                                                                     | Licence                                                                                          | Use and copying status                                                                                                                    |
| -------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------- |
| Regex Tools                      | Release identity `v0.4.0`                                                                                                                                  | GPL-3.0-or-later                                                                                 | Application source written for this project.                                                                                              |
| Toolbox SDK                      | `53c40a61ba1581246f65773fcbb1c1cfd31ac98e` / 0.2.2                                                                                                         | Apache-2.0                                                                                       | Contract, shell and release conventions; package APIs used, no source adapted.                                                            |
| Toolbox Portal                   | `9347554324299c8ec9dfaec2c9730907736f62c3` / aggregate v0.8.0 / package 0.2.7                                                                              | AGPL-3.0-only                                                                                    | Assembly/lock conventions inspected; no source copied into the app.                                                                       |
| regexpp                          | 4.12.2; pinned npm integrity in `package-lock.json`                                                                                                        | MIT                                                                                              | ECMAScript 2025 syntax provider; normalized in the syntax worker.                                                                         |
| PCRE2                            | Signed tag 10.47; commit `f454e231fe5006dd7ff8f4693fd2b8eb94333429`                                                                                        | BSD-3-Clause WITH PCRE2-exception                                                                | Standalone pinned offline build; verified 8-bit WebAssembly pack shipped, source not vendored.                                            |
| PHP                              | Executable identity 8.5.8; embedded PCRE2 identity 10.44                                                                                                   | PHP License version 4 (BSD-3-Clause), elected through the earlier licence's later-version option | Actual PHP `preg_*` compiler, matcher and replacement runtime; PHP source not vendored.                                                   |
| WordPress Playground `@php-wasm` | `web-8-5`, `universal`, `util`, `logger`, `stream-compression` and `progress` 3.1.46; pinned npm integrities                                               | GPL-2.0-or-later                                                                                 | Self-hosted PHP WebAssembly distribution/host packages; their separate GPL notice is included and recorded in the pack metadata.          |
| WebPerl                          | 0.09-beta; commit `6f2173d29a2c2e3536e1de75ff5d291ae96ab348`; prebuilt archive SHA-256 `5f441249217e90ab378c666f473d4206ab4f44907f6bb0aa8d70834bc38c40dc`  | GPL-1.0-or-later OR Artistic-1.0-Perl                                                            | Unmodified legacy prebuilt pack containing Perl 5.28.1; visibly labelled beta/legacy.                                                     |
| Emscripten used by WebPerl       | 1.38.28                                                                                                                                                    | MIT OR NCSA                                                                                      | Upstream-generated legacy Perl loader/runtime; applicable licence included.                                                               |
| Pyodide                          | Tag 314.0.3; commit `ac57031be7564f864d061cb37c5c152e59f83ad4`; pinned npm integrity                                                                       | MPL-2.0                                                                                          | Reviewed self-hosted runtime pack; no CDN use.                                                                                            |
| CPython                          | Executable runtime identity 3.14.2 in Pyodide 314.0.3                                                                                                      | PSF-2.0                                                                                          | Actual `re` compiler, matcher and replacement runtime; Python source not vendored.                                                        |
| ruby.wasm / CRuby                | `@ruby/4.0-wasm-wasi` and `@ruby/wasm-wasi` 2.9.3-2.9.4; executable CRuby identity 4.0.0                                                                   | MIT for ruby.wasm host; Ruby/BSD and component terms in bundled NOTICE                           | Minimal self-hosted CRuby `Regexp` runtime; pinned npm integrities/notices; fixed file/JSON bridge avoids the JavaScript-eval conversion. |
| TeaVM                            | Tag/commit `ee91b03e616c4b45401cd11fb0cd7eb0daf6649b` / 0.15.0                                                                                             | Apache-2.0                                                                                       | `java.util.regex` class library compiled into the verified Java module; not OpenJDK. Also backs the explicit Scala compatibility profile. |
| Emscripten / libc++              | Emscripten 6.0.4 compiler revision `fe5be6afdff43ad58860d821fcc8572a23f92d19`                                                                              | MIT OR NCSA; Apache-2.0 WITH LLVM-exception                                                      | Compiles the application C++ bridge against libc++ `std::wregex`; toolchain source not vendored.                                          |
| Go                               | Tag 1.26.5; commit `c19862e5f8415b4f24b189d065ed739517c548ba`; official archive SHA-256 `5c2c3b16caefa1d968a94c1daca04a7ca301a496d9b086e17ad77bb81393f053` | BSD-3-Clause                                                                                     | Standard-library `regexp` compiler/matcher and official `js/wasm` runtime.                                                                |
| Rust `regex`                     | 1.13.1; commit `2b527599eb9eea0dcc288c704584f242f26a5c61`; crate checksum `f020237b6c8eed93db2e2cb53c00c60a8e1bc73da7d073199a1180401450218d`               | MIT OR Apache-2.0                                                                                | Actual crate compiler/matcher built for WebAssembly with the pinned Cargo graph.                                                          |
| Rust toolchain                   | rustc 1.97.1 commit `8bab26f4f68e0e26f0bb7960be334d5b520ea452`; wasm-bindgen 0.2.126                                                                       | Apache-2.0 OR MIT plus bundled component terms                                                   | Exact compiler, standard library and binding tool identities recorded in pack metadata.                                                   |
| .NET                             | SDK 10.0.302 / runtime 10.0.10; runtime commit `f7d90799ce`                                                                                                | MIT plus bundled third-party notices                                                             | Actual `System.Text.RegularExpressions` browser-WASM runtime.                                                                             |
| ECMAScript specification         | <https://tc39.es/ecma262/>; living specification inspected 2026-07-24                                                                                      | ECMA terms                                                                                       | Semantics reference; no prose copied.                                                                                                     |
| regex101                         | <https://regex101.com/> and public parser documentation                                                                                                    | Product/commercial terms                                                                         | Product reference only. No source, branding, explanations, reference prose or visual design copied.                                       |
| `recheck`                        | 4.5.0                                                                                                                                                      | MIT                                                                                              | Metadata inspected; not installed or shipped.                                                                                             |
| `regexp-ast-analysis`            | 0.7.1                                                                                                                                                      | MIT                                                                                              | Metadata inspected; not installed or shipped.                                                                                             |
| RegexHub                         | Repository revision `d1d9f19d259745dfdd21935b9ef3e747b62b9bfb`                                                                                             | MIT                                                                                              | Potential future adversarial cases; no file copied.                                                                                       |
| RegexLib                         | Website inspected                                                                                                                                          | Redistribution licence not established                                                           | No fixture copied.                                                                                                                        |
| RGXP.RU                          | Website inspected                                                                                                                                          | Redistribution licence not established                                                           | No fixture copied.                                                                                                                        |

All v0.1.0 through v0.4.0 conformance cases are project-authored. See
`tests/fixtures/README.md`. Runtime pack metadata and adjacent licence/notice
files are authoritative for the exact binary distribution.
