To give a little more info:
In June 2003 people used the PSO Exploit for the first time, which was known
from the DC version already - it was possible for Sega to upload executable updates for PSO while it's online. It was found out that these executables weren't signed in any way, so by spoofing the Sega server one could upload any code he wanted to PSO. There wasn't any use for it back on DC, since it was already able to play homebrew software through other ways, but on the GC it was possible to extract the first ISOs (Action Replay, Zelda, Starfox, Skies of Arcadia, Luigis Mansion IIRC) this way. These ISOs weren't of much use, though, since they weren't playable and contained a lot of garbage data. But GCDev sceneers were quite happy, since they finally could run code on the GC using
PSUL 1.0 and
PSO Loader.
Then, on Oct, 10th 2003 Eurasia first released an internal ISO of
Animal Crossing for GC with garbage data removed and soon thereafter their famous "
Animal Crossing Loader", which allowed sending AC to the GC and execute it from RAM. With AC Loader 1.1 streaming was possible, so a lot more games worked - but very flaky and sometimes choppy. Various iterations later it still wasn't a very reliable way to play backups.
Later a guy named tmbinc made a
chip to replace the GC BIOS (even if you're only remotely interested in console hacking, read this thread, as it contains *lot's* of information), which made it possible to load Homebrew software more conveniently. Based on this chip the Viper team built a modchip for homebrewers that allowed to boot commercial ISOs from the DVD drive with a modified BIOS called "Cobra" in
November 2004, finally.
Later the bootcode from Cobra was extracted by a group calling themselves "Utopia" (I don't know if they're tied to the DC group Utopia, which released the first Boot CD for this system, but I think that's highly unlikely) and
released under the name "Anaconda". This made it possible to boot copies from softmods like SDLoad or Max Drive. This drivecode later evolved to GCOS and was also used by Team Ninja which made a chip caled "Ninjamod" (nowadays they make DS flashcarts... I just don't know which of the two Ninja devices). It is rumored that the people behind the Qoob chips at least based their code on Cobra/Anaconda, but it is said that the versions they have released don't resemble this at all.
There were various issues with sound streaming from DVD, flakey reading from cheap DVDRs and multi DVD games with these chips, but I'm honestly to lazy to get the facts about these straight out... AFAIR Qoob was the first chip that perfectly played most backups sometime 2005, but I honestly don't really remember and around that time I also kind of lost interest in GC backups.
If you know better, please correct me. Sorry, this is mostly from memory with a little research on the Dextrose forums - I didn't even plan writing that long. Most important: GC released November 18th, 2001, first "backup" October 10th, 2003 (=two years), first modchip around November 2004 (=three years).
