Audition CC supports Common Extensibility Platform (CEP) extensions, which enable developers to build integrated panels in Adobe desktop applications.
Developers design the panels using HTML5 and JavaScript. They use ExtendScript to communicate with the application.
The Adobe-CEP repository at Github contains source code, documentation, and community-built extensions.

You can install extensions using the Creative Cloud desktop application. Download from the Adobe Add-ons Marketplace and then enable File Sync in the application to automatically install extensions.
You can use the SDK to create custom CEP extensions. Refer to the documentation and sample code in the SDK.
Download the Audition SDK from the Audition Developer Center.