I have a client of my web based application who heavily uses the data from our system for powerpoint presentations.
We currently allow data to export in more traditional
Well you have two ways of really doing this, without third party tools. The first would be with Automation of PowerPoint, but that requires that your server have PowerPoint installed. The second is to utilize the new pptx file file format and generate the powerpoint document using XML.
I have found that the best way to get started on the XML side is to simply create a powerpoint that does what you want, then save it and look at the XML. You can also review the microsoft documentation. Overall working with the XML formats is pretty easy.
Lastly, there might be some third party items out there, but be careful that they don't require COM automation.