Hello. Since a few years back, BGB is using a new URL, and EZ is linking to the old one. Note that even if the old URL still redirects to the new location, it's no longer officially supported and may break at CJB's (the URL shorterer service) whim.
New BGB URL: http://bgb.bircd.org/
BGB page on EZ: http://www.emulator-zone.com/doc.php/gameboy/bgb.html
New BGB URL: http://bgb.bircd.org/
BGB page on EZ: http://www.emulator-zone.com/doc.php/gameboy/bgb.html