Tracktion Engine is published under a dual GPL3 (or later)/Commercial license.
There are multiple commercial licensing tiers for Tracktion Engine, with different terms for each. For prices, see the Tracktion Developers Page.
The majority of the files in this repository are the copyright of Tracktion Software Corporation and covered by our licensing terms, but please note that it may also contain some 3rd-party code from other open-source projects. It is your responsibility when using this codebase to ensure you comply with the terms of all code within it.