By training I'm a complex differential geometer. In 2023, I left academia to design and sell original mathematical images and objects online at Differential Geometry, and to blog about mathematics for non-mathematicians. As a matter of principle I rely on personal mentions and word of mouth for publicity. I warmly invite you to browse, and appreciate your sharing the URL with friends, students, colleagues, and others.

Prior to 2020 I wrote introductory textbooks for real analysis, linear algebra, and group theory, text-based software for creating mathematically accurate diagrams in LaTeX and a miscellany of interactive web-based programs for teaching concepts from algebra, geometry, and (pre-)calculus. I also helped digitize public-domain math, physics, and astronomy books for Project Gutenberg.

I am never deliberately condescending or insulting.

"Hwang" rhymes with "song" more-or-less.