Inferno 7C1023e

Inferno 7C1023e is, apparently, an internal firmware used for testing. It was discovered on an iPod touch (3rd generation), but may be in use on other devices.

Legacy
Although Inferno comes in an IPSW, flashing it via iTunes causes an error. Inferno is flashed using PurpleRestore.

Interface
All tests are performed via a usbmux interface. During that time the iPhone displays a picture of a fireball. Partial output is displayed at the bottom.

However when display tests are run, different output is produced.

Toolkit
After booting up, SwitchBoard.app is shown, allowing you to choose multiple different applications.

They consist of:
 * ATCommand
 * BurnIn
 * CameraFA
 * Operator
 * Rumble
 * SkankPhone
 * Soundwave

Binaries
The firmware includes standard set of UNIX binaries. apt-get is present, suggesting that there is an internal APT repository.

Media

 * Photo 1
 * Photo 2

Source
This was first seen on Sonny788's Twitter.