This site uses the JMdict, Kanjidic2, JMnedict and Radkfile dictionary files. These files are the property of the Electronic Dictionary Research and Development Group, and are used in conformance with the Group's licence.
Example sentences come from the Tatoeba project and are licensed under Creative Commons CC-BY. And from the Jreibun project.
Audio files are graciously provided by Tofugu’s excellent kanji learning site WaniKani.
The SKIP (System of Kanji Indexing by Patterns) system for ordering kanji was developed by Jack Halpern (Kanji Dictionary Publishing Society at http://www.kanji.org/), and is used with his permission. The license is Creative Commons Attribution-ShareAlike 4.0 International.
Kanji stroke diagrams are based on data from KanjiVG, which is copyright © 2009-2012 Ulrich Apel and released under the Creative Commons Attribution-Share Alike 3.0 license.
Wikipedia data comes from the DBpedia project and is dual licensed under Creative Commons Attribution-ShareAlike 3.0 and GNU Free Documentation License.
JLPT data comes from Jonathan Waller‘s JLPT Resources page.