Third-party licences
Last updated 28 July 2026
axe-core
Skiplink's scanning is performed by axe-core, the open-source accessibility testing engine. We run it unmodified and call it through its public API.
Skiplink uses axe-core, an open-source accessibility testing engine distributed by Deque Systems, Inc. under the Mozilla Public License 2.0. The full license text is available at mozilla.org/MPL/2.0. AXE and AXE-CORE are trademarks of Deque Systems, Inc. Use of the axe-core library in Skiplink does not imply endorsement, sponsorship, or affiliation with Deque Systems, Inc.
We do not modify axe-core's source files. Any rules we add live in our own separate files and are identified as ours in scan output.
Other open-source software
| Component | Licence | Used for |
|---|---|---|
| axe-core | MPL-2.0 | Accessibility rule evaluation |
| Playwright | Apache-2.0 | Driving the browser that renders each page |
| Chromium | BSD-3-Clause and others | The rendering engine itself |
| Go standard library | BSD-3-Clause | The API server |
| PostgreSQL | PostgreSQL Licence | Accounts, usage and scan storage |
| Redis | RSALv2 / SSPLv1 | Scan queue, quota counters, rate limiting |
| go-redis | BSD-2-Clause | Redis client |
| lib/pq | MIT | PostgreSQL driver |
| Prometheus client | Apache-2.0 | Metrics |
| sentry-go | MIT | Error reporting |
| ioredis | MIT | Redis client in the scan worker |
Our own code
The skiplink CLI and the GitHub Action are MIT licensed. The API server and dashboard are proprietary.
Questions
Licensing questions go to [email protected]. If you believe something is attributed incorrectly here, tell us and we will fix it.