The tools behind our media.

Narration voices

Narration voices are generated with bilibili IndexTTS2 under the bilibili Model Use License Agreement (github.com/index-tts/index-tts). Any modifications made to the original model in this Derivative Work are not endorsed, warranted, or guaranteed by the original right-holder of the original model, and the original right-holder disclaims all liability related to this Derivative Work.

Some narration, including the lecture sample, uses Qwen3-TTS (Apache License 2.0).

Music

Some background music in our videos comes from Mixkit and is used under the Mixkit Stock Music Free License (mixkit.co/license); the rest is our own.

Type

Instrument Sans and Instrument Serif, by Instrument, under the SIL Open Font License 1.1.