IntelliSense is Microsoft's system for showing the possible completions for a partially-typed object, method or variable name. It is used in various versions of VisualStudio, and is a helpful aid in reducing the need to type hopelessly long names. When triggered after typing a period or a ->, IntelliSense shows all of the members of an object or class, thus allowing user to select the needed item instead of typing it from memory.

Not that original, in fact, since ''many'' IDEs have it since at least 1998. They just call it with a more mundane word: AutoCompletion.

In a development environment without strong browsers, this is imperative: without it developers use too much of the wrong parts of their brains to do the keyboard entry that is the least important part of their job. Actually, having developed in EclipseIde (also with AutoCompletion) I kind of miss having completion in the SqueakSmalltalk editor panes, too.