A feature of a text editor which displays different parts of syntax for types of code in different colors, fonts, and/or styles. The intention it to make it more apparent what a section of code is and what it does by just being able to glance at the editor.

It also helps catch some errors. For example, the lack of a second quotation mark (") on a string will cause long sections of code to show up as belonging to the string, making the error quite apparent. This also applies to comments.

After you get used to using it, you'll find it difficult or impossible to switch back.

Many IDEs have it, and a number of text editors, such as emacs, also have it.