Daljit Dhadwal

Credit: ©iStockphoto.com/Franck Boston

J is an obscure, but potentially very useful programming language for certain types of tasks. It’s a calculator language, and its specialty is manipulating arrays. J was created by some of the same people who made APL. Here’s a great primer on getting started with J, and here are some books on learning the language. You can download J for free, and it recently became an open source project.