Ive always been curious how certain types of content is generated, things like PDFs, dynamic images, and the like - or at least how they are done on-the-fly. I never really bothered to look it up, until I stumbled upon an article about it. I was really looking into build path exclusions in eclipse (cant get it working right in ZS 7.1.1), but this distracted me lol.
Good articles that explain the process:
This one is more in-depth with more examples: http://static.nyphp.org/talks/gd-Lib...nipulation.pdf