Depends which type of file and how old.
AppleWorks 6: WP openable by Pages, SS openable by Numbers, PR openable by Keynote. DR openable by (some versions of) Eazy-Draw. DB and PT openable only by AppleWorks 6.
AppleWorks 5 and earlier: openable only by AppleWorks/ClarisWorks (same of newer version that the version creating the file).
More detailed answer here: Abandoning AppleWorks.