Here's a bit of weirdness for you. Today I compiled cDocumentTemplate and dropped it into a Python library to see what impact it would have on some very intensive DTML in an application of mine... and it actually *slowed down slightly*. I couldn't believe it, so I started doing all sorts of tests. I should note, however, that my 'pDocumentTemplate' has been patched to use the C version of MultiMapping from the ExtensionClass kit rather than the Python MultiMapping. Anyhow, here are some of the results: pDocumentTemplate: ~9 seconds of CPU cDocumentTemplate: ~12 seconds of CPU pDocumentTemplate + render_blocks from cDocumentTemplate: ~8 seconds of CPU Same, with -X option to Python: ~7 seconds of CPU I noticed that there were often dramatic differences in speed depending on whether -X was used. It seems that Python 1.5's class-based built-in exceptions can be hell on DocumentTemplates (and presumably upon Acquisition as well). Any ideas why cDocumentTemplate's InstanceDict and TemplateDict would run slower than the Python versions (given a C MultiMapping)?