Ask HN: What are your favourite micro blogs?

I don't have to time to read all those detailed blog posts about interesting topics. I feel that many blogs bloat their overly-lengthy posts with a soup of keywords to improve SEO while making them annoying to read.

I'm looking for good micro blogs that post short, to the point articles. I like when they link their sources and further reading material on the topic. And if they provide a feed I can subscribe to, I might even read them.