WordPress allows you to have multiple theme directories, but moving themes from one to another may result in a fatal error. It's possible to fix that by updating a few options and clearing a transient.
Reading Stop Breaking the Web by Nicolás Bevacqua's feels like a breath of fresh air.
He writes about how several common practices in the JavaScript community have led to poor user experiences, and violated some of the fundamental principles that made the Web what is today...
I needed a list of countries where ideographic languages are common, but couldn't find a pre-made one. I was able to build one myself, though, which will hopefully save others from having to do the same.