Good article! I've been struggling to grasp what these new "effects" were.

When I had been in university twenty years ago, I had constructed a language with "effects" as I had understood them then: side-effects annotations. I could not in my head recognise how the new effects were like those I had read about in the literature back then.

More recently, I've been working on a compiler back-end/runtime in my (too much) free time with support for resumable exceptions. I didn't know it before, but after reading this article, it appears that the runtime actually does have support for "effects", without me really trying.