raganwald.com uses github’s md-to-html thingy, which is jekyl.
But there is nearly zero walled garden downside. I own the domain, I don’t use github.io, so I don’t fear link rot if I move.
Because it’s git, I always have a copy of everything locally, I don’t depend on github for storage.
Because it’s jekyll, I can generate my blog on my own system and upload it somewhere else whenever I want.
I don’t support comments at all, but that’s a personal choice. I’m not in the community business, I outsource comments to Hacker News. Which is also how most of my readers want to discuss my writing.