GitHub Pages has upgraded to Jekyll 3.1.6, bringing significant performance improvements by using Liquid::Drops instead of Ruby Hashes for on-demand metadata calculation, which should be seamless for most users but requires local testing with the GitHub Pages Gem to ensure site builds as expected. Key changes include accessing front matter in layouts through {{ layout }}, with proper merging of child and parent layout values, such as layout.color reflecting child-defined values. Users of the Jekyll Bootstrap theme need to update _includes/JB/setup for compatibility. Jekyll 3.1.6 introduces over 100 changes, including bug fixes and enhancements to rendering and previewing, with detailed changes available in the Jekyll changelog.