# DDN — notices and sponsorship

Copyright (c) 2026 ScratchBird Software Inc. and DDN contributors.

DDN (Diagram Design Notation), its viewer, visual designer and verifier are free,
open-source software for general public use, sponsored by
[ScratchBird Software Inc.](https://scratchbird.ca).

DDN's own implementation, documentation, examples and website code are
licensed under the GNU General Public License, version 2 or (at your option) any
later version (`GPL-2.0-or-later`). You may use, study, modify and redistribute
them under that licence. DDN is distributed without warranty; see the complete
[GPL text](LICENSE).

The [public DDN project](https://github.com/ScratchBird-Software-Inc/Diagram-Design-Notation)
is the home for source, releases and contributions.

## ScratchBird systems software suite

- [ScratchBird Software Inc.](https://scratchbird.ca) — sponsor and suite home.
- [Weaver](https://scratchbird.ca/weaver) — the separate commercial platform for
  collaboration and connected design, built on the DDN foundation.
- [ScratchBird CDE](https://scratchbird.ca/bird) — the suite's data platform.
- [ScratchRobin](https://scratchbird.ca/robin) — the suite's client application.

DDN works independently in the browser. Its GPL licence does not require a
Weaver subscription, and Weaver's separate commercial terms do not restrict
use of DDN under the GPL.

## Third-party resources

Bundled third-party resources retain their own licences and attribution.
The optional Inter, Source Serif 4, JetBrains Mono and Caveat fonts use SIL Open
Font License 1.1; distributed font packs include `ddn-fonts-LICENSES.txt` and a
provenance manifest. Tabler and Iconoir icon selections retain their MIT notices.
Other artwork carries the licence and provenance supplied with its asset pack.
Preserve these notices when redistributing the resources.

Standards and product names identify supported notation conventions or design
references. They do not imply endorsement, affiliation or certification.