In the first version of the chart I had column for "XML". But it didn't looked good, because there was only 1 candidate for XML and that was Maven. That's why I dropped it again. Beside that I think that XML is kind of overkill for dependency management. JSON is just fine, much smaller and easy to read. Having the dependency definition in native code (Python, Groovy, whatever) is not a good decision, in my opinion, because that's a source for security vulnerabilities.