Invented by Adobe Systems over 20 years ago, the Portable Document Format (PDF) is now an open standard for electronic document exchange maintained by the International Organization for Standardization (ISO). When you convert documents, forms, graphics, and web pages to PDF, they look just like they would if printed.
PDF
Every glyf inside a PDF file can have a display value and a different extraction value. This is useful because often you need to... Text is defined in the PDF file format as a display value (normally what you see onscreen) and an extraction value. It is useful... A PDF file are designed to be resolution independent – they are defined using resolution independent units so that the page will always appear... We get lots of emails asking about fonts so this articles tries to explain some of the potential issues. Loading fonts All fonts used... Did you know that PDF files can actually define spaces in several different ways? Three common ways I have found of representing spaces between... The PDF file format allows you to embed video directly inside a PDF file. So, I wondered, how easy would it be to write... 
