I'm a big fan of
Chalk theme by Nielsen Ramon for Jekyll and personally I was missing a working gem-based version of the theme. There are a few gems that attempted to do that by I wasn't able to get either one of them working (even being a developer myself)...
So, I set out myself on a mission to fix that and the net outcome of this endeavor is
jekyll-theme-chalk gem published in RubyGems.org.
However, one thing is to publish a gem and another thing is to consistently maintain it. To make it less frustrating and be able keep up with the latest changes (since the original theme sources are in another repository) I put together a few tools that help downsize the friction and maintenance cost...
These tools are jekyll-theme-specs, jekyll-theme-assets and jekyll-theme-pages.
Oh, and I also put together a very basic sample site using gem-based version of Chalk theme in this repository: