In my case, until I sort through the diskettes I don't know what program(s) created the files. The one that I unearthed that started me thinking I should try to save some of these antiques is a 5-1/4" diskette (or two or three -- haven't opened the package to check) with a bunch of TrueType fonts on it. Until I can see what they are, I don't even know if there's anything there that's not being offered now built into Windows, but back then, when TrueType was new, the "native" selection was comparatively limited.
Others are probably WordPerfect documents, Quattro Pro spreadsheets, and possibly some Generic Cadd drawing files that probably nothing will read today.