Heimdall is a cross-platform open-source tool suite used to flash firmware (aka ROMs) onto Samsung Galaxy S devices. Heimdall uses the same protocol as Odin to interact with a device in download mode. USB communication in Heimdall is handled by the popular open-source USB library, libusb-1.0.
Why “Heimdall”? The flashing software Odin is named after the king of gods in Norse mythology. Loke, the software component on the Galaxy S that provides functionality to flash, may also to be named after an important character in Norse mythology, often translated as Loki. As such I have named my flashing software Heimdall, after the Norse god, and guardian of the Bifrost Bridge.
What platforms does Heimdall run on? Linux, OS X and Windows (XP, Vista, 7 etc.)
Why use Heimdall when we can use Odin? Odin is generally unreliable and only runs on Windows systems. Furthermore, Odin is leaked Samsung software that is not freely available or well understood by the community.