The Define-XML v2.1 stylesheet was initially published in May 2019 by CDISC as part of the Define-XML v2.1 package. This version can be found in the cdisc-2019 folder and also in the publish folder.
The updated Define-XML v2.1 stylesheet in the localization folder adds localization to enable HTML rendition in any language (English, Chinese, Japanese, ...).
The scripts folder contains some example scripts to convert a Define-XML document to an HTML file by utilizing a stylesheet.