Thanks very much indeed for your response – it is much appreciated!!

I couldn’t see where the render() method gets called when using the taglib. However, if the org.zefer.pd4ml.taglib.PD4MLTransformerTag variable is a local variable, I assume that the render() method belonging to the same pd4ml instance is not called by more than one thread at a time?

Thanks for the performance warning about executing multiple conversions simultaneously. We want to allow customers on our website to generate pdf quotations from the jsp page which displays their shopping basket. We anticipate a maximum of 100 quotes per day. However, I am very concerned about putting too much load on system resources and will certainly monitor it. I may have to change the default quote option from pdf format to excel format (which is the format we have been using all along).