Other World Computing (OWC) has expanded the low end of its popular Mercury Extreme line with a 700MHz G4 processor upgrade available immediately for US$199.99. OWC also reaffirmed that the entire Mercury Extreme line, from the G4/700MHz model to the current top end G4/1.4-1.467GHz model, is 100 percent compatible with all Mac OS versions, including Mac OS X 10.3 Panther.