The 25 Carnival of Mathematics is in town at Teaching College Math Technology Blog, run by Maria Anderson. Most of her entries are about technology — using it, improving it, etc, although there are some non-tech ones like this Mathmaticious video. Some of my recent favorite entries are a simulation of Leibniz’s calculating machine and a recent discussion about open source textbooks.
The Carnival itself has an assortment of articles from Tic Tac Toe to Linear Equations. Enjoy!