1. TEI based XML format at DHQ. Documentation.
2. JATS based XML at de Gruyter and tons of other publishers.
3. DocBook and Balisage-1.3 at Balisage. Example
4. XLingPaper XML —

https://relaxng.org/tutorial-20011203.html
https://www.w3.org/2000/04/schema_hack/

https://www.balisage.net/Proceedings/vol21/print/Tovey01/BalisageVol21-Tovey01.html

https://typeset.io/resources/typeset-evolving-into-scispace/
https://typeset.io/resources/jats-xml-everything-a-publisher-needs-to-know/

JATS in multilingual books:
https://www.ncbi.nlm.nih.gov/books/NBK579699/

JATS
https://www.escienceediting.org/upload/kcse-284.pdf
https://jats.nlm.nih.gov/jats-con/2013/presentations/graham2013.pdf
https://github.com/ncbi/JATSPreviewStylesheets/blob/master/xslt/main/jats-xslfo.xsl
https://assets.pubpub.org/z1qlpyk6/01566244075411.pdf

https://av.tib.eu/media/51339
https://github.com/pkp/texture
https://jats.niso.org/jatswiki/index.php/Tools
https://www.ncbi.nlm.nih.gov/books/NBK425544/

Interesting examples:
https://typeset.io/papers/defining-a-linguistic-area-south-asia-gilv2538jj
Pricing:
https://typeset.io/account/pricing/?source=plans-billing-page