Didn't know Plotkin had a blog, thanks for sharing this! He's never been quite my style as far as IF authors/creators go, but I can't deny that he is an incredible font of information.
Also, just because IF doesn't come up much, here are some of my favorite IF games for anyone who wants to play one (and you should!):
Games about words
Counterfeit Monkey - Emily Short
A masterful game by one of the best IF creators, and has one of my favorite items in all of fiction: a gun that lets you remove one letter from a word, and thus alter reality. A "pear" can suddenly become an "ear", and someone's tasty snack will suddenly become quite a bit less appetizing. Think of it as "Portal for the English language". Each puzzle has quite a few solutions, and you are limited only by your cleverness.
Ad Verbum - Nick Montfort
A smartly written puzzle game that relies on clever wordplay and themed rooms. Light and engaging.
Suveh Nux - David Fisher
By far my favorite one room game. Anyone with an interest in linguistics and "thinking your way out" should check this out. A pretty fast game about unearthing magic.
Games about Games
Endless, Nameless - Adam Cadre
My favorite IF game. Part throwback love letter to old school IF, part metafictional metaphysical rollercoaster. If you've played an IF game before, I cannot recommend this game enough. You will DEFINITELY need to download it and play it on your computer, not online. Make use of saves.
Words about Words
Galatea - Emily Short
A beautiful character study that is incredibly executed from a syntax/programming standpoint.
Eurydice - Anonymous
It's, uh, real sad. A retelling of the classic myth.
Aisle - Sam Barlow
By the creator of Her Story. A one word game.
NOTE: I only picked freely available modern games because it's a bit harder to find legal ways to play older ones. Obviously, play Zork Sorceror, Adventure, etc. if you can find a copy of them.