When I switched this blog from WordPress to Jekyll I ended up writing a bunch of Jekyll plugins to make the transition easier. I've updated the code section with the first plugin - jekyll-archive-page.
One thing I missed from WordPress was a nice archive page, so I wrote a simple plugin to build an archive page (the archive page for this site uses it). I based the output the "Smart Archives Reloaded" plugin for WordPress, although I don't use any Javascript.
It's nothing too fancy, and the code isn't very elegant, but it gets the job done.