iBooter is an interactive console for iBoot (the apple bootloader). Most of you would have used iphuc, which uses iBoot. However, it's dependant on iTunes the mobile device library and can't get replies from iBoot, which results in one way communication, where you blindly say cmd setenv foo, but you never know what happened.
With iBooter you can debug phone booting issues as well as run it in Linux/MacOS/Windows without iTunes installed. You can use iBooter to read memory/write memory, load ramdisks, change your wifi mac address, read files from nand and much more! http://www.iphonelinux.org/ibooter