Thank you! Until a few years ago, this project ran on PHP. It was then later rewritten in Common Lisp. I published the Common Lisp source code for this website only about a week ago. That's why I thought of making this "Show HN" post today.

Until now, the source code published on GitHub has usually been a few versions behind the live website running at https://mathb.in/ but I am hoping that in future, I will keep the source code on GitHub as recent and as updated as possible.

What was the motivation and how was the process of the rewrite?

There were two main motivations: simplifying the code and the features, and writing the software in a programming language that I enjoy programming with.

The process of the rewrite was roughly like this: simplifying HTML, CSS, and JavaScript code first, then switching from MathJax v2 to MathJax v3, then making corresponding changes in the JavaScript code, then replacing the custom Markdown + LaTeX demultiplexing logic with TeXMe that is specifically designed to solve this problem, and finally rewriting the server-side functionality in Common Lisp. The last activity had roughly six phases of development: writing some of the utility functions I would need later (e.g., parsing posts, storing/retrieving posts, etc.), writing tests, presenting the home page, processing the post submission, presenting post pages, and performing post validations.