(Update: I've also tried Windows own built-in Compressed Folders to open the archive (on Windows 7), but it reports
Unspecified Error 0x80004005 on the archive. Presumably, that means Windows itself doesn't support this compression method, either.)
I've already asked the person to avoid using a non-standard compression method and re-send the file. I know WinZip (of which they are using a newer version) has compatibility options. But, I'm wondering:
What archiving utilities, other than WinZip, support this "compression method 98"?
In particular, is there a free and/or open source tool that supports that method? If not, why not? Is the method strictly proprietary to WinZip?