What does Emacs mean?
Emacs is a class of cross-platform highly-customizable text editors created by Richard Stallman. The first Emacs was released in 1976. Today, Emacs is developed under the GNU project and written in C and Emacs Lisp. Emacs has many types, but GNU Emacs and XEmacs are the two most popular versions.
Emacs text editors offer different content-sensitive modes for plain text, programming source codes and HTML code. Such modes feature syntax highlighting, where different colors are used to highlight different syntax elements (like loops, comments, variables, etc). This feature can make program code easier and faster to read, and consequently quicken development.
Techopedia explains Emacs
Emacs is one of the two most widely used text editors in the Unix and Linux platforms. It can be downloaded for free from the GNU site or from numerous mirror sites around the world.
Emacs is more than just a text editor; it can also issue shell commands, access the Internet, write and test programs, and read and send emails within the Emacs environment. Becaus it is a cross-platform program, Emacs can run on a variety of operating systems, including Windows, Mac OS X, Linux, FreeBSD, SunOS, Solaris and OpenBSD. Emacs can be further extended or customized using Emacs Lisp, a dialect of the Lisp programming language. Emacs Lisp includes numerous extensions such as a project planner, calendar, debugger interface, and a mail and news reader.
Another useful feature that renders text and code more readable is automatic indentation. Emacs identifies blocks of code and groups them accordingly. It also provides Unicode character support for practically all writing systems and languages, and features self-documentation, which automatically generates and displays documentation for every command, variable and internal function found in a program’s source code.