A new post on the LooPo blog points out a handy PHP library to make and work with PDF files in PHP - Portable Document Markup Language (PDML).
I was curious how this works, as it seemed pretty different from previous similar libraries (PDFLib, FPDF), that offered a programmatic API to generate PDF DOMs instead of a markup language.
They describe how it works, what's included with the download and how it uses output buffering to get the job done as well as a few updates and further tips on its usage.