[Zope] Product for Out-of-Process jobs

Hello, I need to generate some huge PDF-report out of process. So the user sees some waiting screen, while the report is generated. When generation is finished the report is delivered. First I did it with Threads. It was a pain, but the waiting screen worked. Now I do it with ZEO, but the waiting screen doesn't work any more. I'm now finally thinking about a generic product allowing me to do a task out-of-process. Could someone please tell me how to get things done without threads. I have already read http://www.zopelabs.com/cookbook/1058719806 . But the line pdf = ReportGen().createReport(report()) is a bit cryptic to me. Is someone interested in helping me with this product? With kind regards Florian Reiser