Today I got to test out popoon a little, its very easy to get up and running. I was able to transform an XML document to HTML using libxslt, which is the best part of nexista in my humble opinion. Converting nexista and the nexista-based applications I've worked on is a high priority. I'll likely keep pbooks "as-is" for now, but some of the new projects I'm releasing, like infonomix, will be compatible with cocoon's sitemap specification. Also regarding python, I just did a quick search and there is a python-based ant project. Cool! I'm working on some comparison documents here: http://www.nexista.org/wiki/Nexista_Cocoon_ComparisonWith regards to Popoon, I notice that they mix PHP processing instructions with XSL, which I have purposely avoided doing.