Alpine 4A57

Alpine 4A57 is a prototype firmware found on an iPhone Prototype discussed on macrumors. According to a photo of it, it was an internal version of iPhone OS 1.1.3.

Applications
Unlike previous builds, this one seems to not be as reliant on SkankPhone and also has SwitchBoard.app. Upon booting, the user can choose from six applications:
 * ATCommand
 * BurnIn
 * Operator
 * Rumble
 * SkankPhone
 * Soundwave

Restore
Instead of restoring via a ramdisk, the restore tools appear to be right in the OS, suggesting restores were originally performed through userland.

Baseband

 * The iPhone Prototype came with 04.02.13_G

Flashing 04.02.13_G on a retail iPhone can be done with bbupdater, but results in loss of Carrier Network connectivity.