There also exists the "Fortuna" exploit (and also recently reimplemented and documented as open source "OpenTuna"), which uses a buffer overflow in the memory card icon reading code, providing a disc-less exploit for the later models of PS2 (including the "PS2 TV", aka the Sony Bravia KDL-22PX300 television set including a built-in PS2 console)

With FreeMCBoot and Fortuna, all PS2 consoles can be exploited from boot time. With FreeDVDBoot, it provides a convenient entrypoint to install the aforementioned exploits.