Jekyll is a simple, extendable, static site generator. You give it text written in your favorite markup language and it churns through layouts to create a static website. Throughout that process you can tweak how you want the site URLs to look, what data gets displayed in the layout, and more.
Using with Drupal
Drupal 7 Importer - currently no completed Drupal 8 importer exists.
Any custom approach to export Drupal data as Yaml, Json, or CSV can then be consumed by Jekyll.
Create a Drupal generated RSS feed to export data for use with the Jekyll ESS importer