not to run ePSXe. to run ePSXe u need a PSX BIOS (read the rules and don't ask for it). there is no application that I can think of that currently requires a PS2 BIOS (other than the PS2...but u knew that)
Now it certainly does. There is only one Ps2 emulator that exists today that doesn't require a BIOS file to run, I for get the name of it. I wouldn't recommend it anyways due to low compatibility... that one can run 180 or so games, whereas PCX2 claims compatibility with 98% of the entire library of Ps2 games, which is a massive difference.