Jekyll has the significant advantage of support Asciidoc out of the box as Asciidoctor is written in Ruby. We really need alternative asciidoc implementations.
Both, the original and asciidoctor, offer a CLI tool to convert asciidoc to different formats (and there is always pandoc). Additionally, asciidoctor aims to integrate with JVM languages courtesy of JRuby. So you have multiple implementations callable (in one way or another) from any language imaginable.