There are a number of (optional) extra features that Jekyll supports that you may want to install, depending on how you plan to use Jekyll.

Web Highlights and Commenting

Register your site with txtpen. Then append

<script src="https://txtpen.com/embed.js?site=<your site name>"></script>

to your template files in /_layout folder.

Math Support

Kramdown comes with optional support for LaTeX to PNG rendering via MathJax within math blocks. See the Kramdown documentation on math blocks and math support for more details. MathJax requires you to include JavaScript or CSS to render the LaTeX, e.g.

<script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-AMS-MML_HTMLorMML" type="text/javascript"></script>

For more information about getting started, check out this excellent blog post.

Alternative Markdown Processors

See the Markdown section on the configuration page for instructions on how to use and configure alternative Markdown processors, as well as how to create custom processors.