Converting DocBook to PDF using PHP

[Noah Slater <nslater@gmail.com>]

Hello,

I am still trying to grok DocBook, but I am having a little trouble
figuring out one thing.

I have a file called docbook.xml and another file called docbook.xsl
which I am using to generate HTML output.

I am generating the HTML using PHP's XSL extension. Please do not
think this post is about PHP, because it's not - I have no problem
with PHP.

The way the extension works is quite simple. It takes a XML file (in
this case, a DocBook file) and applies a XSLT file to get some output.
It's as simple as that.

Now, onwards to my query. Is it possible with this simple model to
transform my document to PDF?

I have looked for hours on the web at many sites, but they all seem to
focus on command line tools (such as tex and LaTeX etc) for the
transformations. I do not want to do this, as the target application
of all this is a simple website that can offer PDF files generated on
the fly from DocBook files.

Does anyone have any ideas or pointers? Is it simply a matter of
getting the right XSL file that can do this for me? If so, are there
any free (as in speech) one's on the web?

Thanks guys, your help is greatly appreciated!

Noah