The world in which IPv6 was a good design, by Avery Pennarun.
Linux Load Averages: Solving the Mystery, by Brendan Gregg.
Sufficient conditions for sound tree and sequential hashing modes, by Guido Bertoni, Joan Daemen, Michaël Peeters, and Gilles Van Assche.
Celebrating 30 Years of HyperCard, by bringing it back via archive.org!
EurKEY, the European Keyboard Layout.
Included in X11 as setxkbmap eu.
The Goo programming language, preserved. 15 years, how time passes.