Hello - Pb with the HTML docs

Hello! I have downloaded the Acrobat version of the PHP documentation and it works fine, thank you. But finding it a bit unwieldy, I sought to use the HTML version. That's where it comes down: I'm using an old iMac (as old as they get, ie October '98) with System 8.1 and am trying to unzip the file with ZipIt, that (I insist) worked fine with the Acrobat manual. For some reason, ZipIt will either refuse to recognize the file as really zipped, or outright crash. Can you help me ? Thank you, jd