People that want web-apps usually also need PDFs, so we went 3 
different ways to produce PDF, each with its advantages and 
disadvantages:

- SPDF is a native Smalltalk library that I ported from VisualWorks: 
  it is very fast, can directly stream to sockets and provides a nice 
  object-representation of PDF files. However it requires that you 
  know about the internals of PDF and since there are no 
  font-metricts, it can't do line-wrapping automatically.

- Latex is another way to create PDF: It is not so fast, but 
  especially for Seaside applications it can be very interesting. What 
  we did, is to create a new back-end to Seaside, so that we can 
  render the same components to produce Latex instead of HTML. This 
  works very well, however there are no means to directly control the 
  position of elements. Line-wrapping works of course.

- Morphs are the third way to create PDF. Export them as PS and 
  convert them to PDF using ps2pdf. With this approach it is possible 
  to do exact positioning, line-wrapping, etc. but it is not very fast 
  and multi page documents do not work nicely (you have to have one 
  morph per page).

I know that other people have other solutions for this problem, these 
are just the ways we went to satisfy different requirements. You might 
also want to look at FOP, a tool that generates all kind of output 
formats from an XML specification.

Cheers, Lukas