not really open source, but all of your data is safe as markdown files. While normally prefer FOSS applications, I make an acception for Obsidian, because nothing really matches it
Reading this article, a scenario played out in my head: what if Papirus and other Icon-theme developers stopped making proprietary apps' icons? "you can use any software you want, but you only get a fancy icon if it's FOSS"
Imagine a poop flavored button