Something really cool I found a while ago, and have started to use again recently is the ability to programmatically control OpenOffice (http://www.openoffice.org)

I have used this in a VB.NET application I wrote that will look into a drop folder for a .RTF file, and convert it to a .PDF file. It took me a long while to work out how to (for free) convert a variety of office type documents to a pdf, this was by far the best.

If you would like the main source code for the function I wrote I can post it up here if anyone wants, alternatively check out this article on the code project website http://www.codeproject.com/vb/net/oo2html.asp This was the article the originally helped me out, there is also quite good developer documentation on the OpenOffice web site.