A noninclusive discussion of programming languages.

A shell is a command line (i.e., programming) interface to an operating system, like Unix operating systems. Low-level programming languages deal with a computer’s hardware. The process of moving from the literal processor instructions toward human-readable applications is called “abstraction.” Low-level languages require little abstraction. Interpreted languages are quicker to test (e.g., to run a few lines of code); this facilitates learning through trial and error. Interpreted languages tend to be more human readable. Compiled languages are powerful because they are often more efficient and can be used for low-level tasks. However, the distinction between interpreted and compiled languages is not always rigid. All languages presented below are free unless noted otherwise. The Wikipedia page on programming languages provides a great overview and comparison of languages.