Adobe Systems, Inc. http://www.adobe.com owns the product.

PlanetPDF http://www.planetpdf.com, is a treasure-trove of information and resources, including discussion forums for users and developers.

PDFzone http://www.pdfzone.com is the “the online authority for PDF, Adobe Acrobat and related document technologies, dedicated to energizing the PDF community with unbiased news reporting, timely interviews, expert resources and vibrant discussions.”

Microtype's Shlomo Perets is an Acrobat guru and regular expert contributor to online forums including the FrameUsers and PDF discussion lists. Lots of PDF and FrameMaker items and info available. http://www.microtype.com