I think a middle ground has been reached, XSLT 3.0 allows you to transform your XML into JSON and back. The XSLT 3.0 (2017) processor is available to non-Java

I think a middle ground has been reached, XSLT 3.0 allows you to transform your XML into JSON and back. The XSLT 3.0 (2017) processor is available to non-Java languages from Saxonica, for Python "pip install saxonpy" (Linux only) If you want to see how to do these XML-to-JSON and JSON-to-XML transforms I have written a little learning repo with a CLI: https://github.com/aleph2c/leaning_xslt https://github.com/aleph2c/leaning_xslt Here is Michael Kay's white paper on Transforming JSON using XSLT 3.0: https://www.saxonica.com/papers/xmlprague-2016mhk.pdf https://www.saxonica.com/papers/xmlprague-2016mhk.pdf Once your data is in a JSON format, you could implement your compact-binary-format idea around it.