This is server API (go to client)

Module Eliom_pervasives.​HTML5 

module HTML5 : sig..end

Building and printing valid (X)HTML5 tree. 

module M : sig..end

Typed interface for building valid (X)HTML5 tree.

module P : 
  XML_sigs.TypedSimplePrinterwith type 'a elt := 'a M.elt
					  and type doc := M.doc

"Polyglot" HTML5 printer.