This website was made using following free software projects:
Design is based on MIT licensed Hugo theme Hello Friend authored by panr (I rewrote parts of HTML / SASS / JS code because I don't use Hugo)
Layout of the page with notes and singular note page borrowed from hermit Hugo theme by Track3. I liked it more so created kind of hybrid of two Hugo themes.
Light / dark mode icon (visible in upper left corner on desktop) and favicon is MIT licensed, authored by Bootstrap Icons 1.8.1 project.
I wrote it as experiment using Crystal language and Kemal micro-framework.