This article discusses software internally used by Apple.
Acquiring a copy without Apple's consent is illegal and may result in being scammed.
A dump of this build's root filesystem is known to exist and is almost 2.0 GB in size. It was discovered on a prototype iPad 2, and is based off of an internal version of iOS 4.3.
This firmware has the kernel version
Darwin Kernel Version 11.0.0: Thu Feb 10 21:48:31 PST 2011; root:xnu-1735.46~2/DEVELOPMENT_ARM_S5L8940X.
This build seemingly has the same set of apps as Durango 8F3178a. Strangely, the regular iOS Camera app is included, although it likely cannot be launched.
The following is a complete list of SwitchBoard apps present in this build: