The Acrobat FDF Toolkit might be what you're after. And they claim there's a Perl API there, too.

I dunno if Adobe are still as actively pushing PDF+FDF as a consumer web form solution as they used to be. Some basic information is in Thomas Merz's "Web Publishing with Acrobat/PDF" (Springer-Verlag, 1998, ISBN 3540637621).

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bowling trophy thieves, die!