The best replacement for jekyll is hyde.

The best alternatives to jekyll are rated as following:
★★★★★  hyde
★★★★★  octopress
★★★★  middleman
★★★  ghost
★★  mr hyde
★★  pelican
★★  nanoc
★  statamic
★  docpad
★  hakyll
★  assemble
★  harp
★  trigger
★  ruhoh
  tybee
  hugo
  mr. hyde
  sphinx

Your alternative for jekyll is not listed? Suggest!
Speaking about jekyll, one probably shouldn't forget about github.

Other search terms related to jekyll and their ratings are:
★★★★★ github
★★★★ haml
★★★★ grunt
★★★ sass
You have in mind a companion for jekyll and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of jekyll in all years. Click on graph for more.
jekyll
hyde
octopress