Btw, XML is alternative syntax that can be chosen for specific books. Does not replace the original Erudite syntax. <div class="gmail_quote"><div dir="ltr" class="gmail_attr">El sáb, 15 de jun de 2024, 23:35, Mariano Montone <<a href="mailto:marianomontone@gmail.com">marianomontone@gmail.com</a>> escribió: </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi all, I'm working on Erudite books authored using XML. Because, if EPUB uses it (HTML actually ...), then why not? :P The real reason is to try to make Erudite books more structured (like support for lists, etc) and easily extensible. I think books have a domain, and the authoring language should reflect that. And so the markup should be easy to extend (I can imagine a <DrGeoExample> element, for example ). XML is very generic, and I'm not having to apply any special rules, like with the PEG parser. And so extending the grammar it is just a matter of subclassing from existing Markup nodes. Also, the source being more structured has better potential for applying transformations to other formats. I attach an screenshot with an example. There you can see a custom <info> node as an example that can be implemented with a class and a couple of methods. I have the impression that extension in documentation systems is not used much, but I think it is a very good idea; and specially like the idea of an "object oriented markup language". I'm interested in your thoughts, either about this, or other documentation systems that support extension (I looked at DocBook but I'm not sure how easy are to implement the extensions. TexInfo supports custom elements via macros, but an object oriented design for the markup has advantages IMO). Cheers! Mariano </blockquote></div>