This article discusses software internally used by Apple.
Acquiring a copy without Apple's consent is illegal and may result in being scammed.
This is a SwitchBoard build that appears to be based off an internal version of iOS 9.0. A filesystem dump weighs in at about 4.6 gigabytes.
This firmware has the kernel version
Darwin Kernel Version 15.0.0: Thu Aug 20 13:13:29 PDT 2015; root:xnu_development-3248.1.3~1/DEVELOPMENT_ARM64_S8000.
Upon booting up, SwitchBoard.app will let you choose from multiple apps. They are: