I think the standard ls doesn't have much in terms of color/icons, so its simplicity probably makes it a great side project for improving on.
Not a big surface area, some easy improvements. A whole lot less stressful than rewriting grep (although I'm massively grateful Burnt Sushi did such a crazy thing)
Thanks @benrutter! You nailed it - ls is like the "Hello World" of system tools. Simple enough that you won't tear your hair out, but meaty enough to learn a ton. Started with "ooh, pretty colors!" and before I knew it I was deep in filesystem APIs and terminal wizardry. Way less scary than tackling grep. Sometimes the best projects are the ones where you can't mess up too badly... well, unless you accidentally delete everything while testing