I have asked about alternative libraries for PDF creation (as in free or source available) in many forums. There is usually no response or the suggestion to use rich text. RTF is viable, but limited for complex commercial documents.
The good news. In my day job I am working on a project to create PDF bank statements "on the fly". One of my developers found a free java library at http://www.lowagie.com/iText/
It works fine (and fast) in our Websphere environment.
For PHP it should work when java support is enabled - as per the article at this web site. I plan to start working on this in a few weks time - and would like to work with anyone else "out there" to explore this sulution.
In any event, the library works and is extendable with a bit of effort.
Chris