secst
SECST is a Semantic, Extensible, Computational, Styleable tagged markup language. You can use it to joyfully create compelling, interactive documents backed by HTML.
The SECST language, reference HTML transpiler and runtime support implementations are currently in :strong[ALPHA], so this package is not updated frequently.
See https://github.com/anywhichway/secst for the most current version.
See the documentation at https://secst.org.