I used to have a ritual - once a year, I would look for a new Markdown viewer and switch to it. Not out of boredom, but because they all suck. Most are built on Electron and a couple of JS libraries, which come bundled with slowdowns, freezes, and gigabytes of memory usage on large documents. The rest either require a subscription or lack basic things like Mermaid diagrams or code highlighting. What I wanted was something small and fast, like Sublime Text, but for Markdown. In the end, I had to build my own, native, optimized for efficiency, and with a full set of features for comfortably reading walls of text: fast search, format highlighting, diagrams, a document map, comparison, zen mode, and so on.