It's FOSS - https://itsfoss.com/asciidoc-guide/
Brief: This detailed guide discusses the advantages of using AsciiDoc and shows you how to install and use AsciiDoc in Linux.
Over the years I used many different tools to write articles, reports or documentation. I think all started for me with Luc Barthelet’s Epistole on Apple IIc from the French editor Version Soft. Then I switched to GUI tools with the excellent Microsoft Word 5 for Apple Macintosh, then the less convincing (to me) StarOffice on Sparc Solaris, that was already known as OpenOffice when I definitively switched to Linux. All these tools were really word-processors.
But I was