How do developers get away with writing .pdf software without paying royalities to adobe?

Question

Example: the processtext company http://processtext.com/

they have dozens of pdf related utilities that do not require adobe's products to be installed. Any while on the subject, are there available code examples for manipulating and processing pdfs?

Answer 1

PDF is an ISO spec which Adobe released without the need to submit royalties.

http://www.adobe.com/devnet/pdf/pdf_reference.html

Edit: here is the legal text which licenses the patent for no charge: http://partners.adobe.com/public/developer/support/topic_legal_notices.html

For editing and manipulating PDFs, it depends on what your framework/language is. I use iTextSharp, a port to .Net of iText, a Java library. More can be found here: http://stackoverflow.com/questions/210029/pdf-libraries.