This site uses hanzi_lookup by Gabor L. Ugray, derived from Jordan Kiang's HanziLookup.
Project: https://github.com/gugray/hanzi_lookup
Pinned upstream revision: 01f90c3ab99a8fadf0696c28e5eb097223c500db

hanzi_lookup.js and hanzi_lookup_bg.wasm are unmodified upstream files.
The library is separately distributed under GNU LGPL version 3 (see LICENSE),
which incorporates GNU GPL version 3 (see LICENSE-GPL).
Complete corresponding source, including the build instructions and embedded
stroke data, is supplied beside these files in source.tar.gz.

The stroke data comes from Make Me a Hanzi and the Arphic PL KaitiM GB and
Arphic PL UKai fonts. Its Arphic Public License is supplied in LICENSE-APL.
The upstream copyright and license notices are retained in the source archive.

The library is provided without warranty. It runs locally in a Web Worker;
the site's handwriting interface does not upload names or drawn strokes.

Local license and source files:
/vendor/hanzi-lookup/LICENSE
/vendor/hanzi-lookup/LICENSE-GPL
/vendor/hanzi-lookup/LICENSE-APL
/vendor/hanzi-lookup/source.tar.gz