Your post was clarifying, and I admit I do not have a great expertise with ithreads (though you seemed to miss the fact that the pages need to be gotten sequentially). The limitations I found that killed the act, at first, were not being able to use shared blessed objects, or classes, for that matter, even because unshared referents are trouble for ithreads. So how could a thread which does the processing call $root->push_content? Your post has given answers to those questions, which I'll study. I think a main thread holding $root and a queue of processed elements to be pushed should be best. Thanks a lot.