TextEdit was the name of a collection of application programming interface

Application programming interface

An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...

s (APIs) in the classic Mac OS

Mac OS

Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...

 for performing text editing.

These APIs were originally designed to provide a common text handling system to support text entry fields in dialog box

Dialog box

In a graphical user interface of computers, a dialog box is a type of window used to enable reciprocal communication or "dialog" between a computer and its user. It may communicate information to the user, prompt the user for a response, or both...

es and other simple text editing within the Macintosh GUI

Gui

Gui or guee is a generic term to refer to grilled dishes in Korean cuisine. These most commonly have meat or fish as their primary ingredient, but may in some cases also comprise grilled vegetables or other vegetarian ingredients. The term derives from the verb, "gupda" in Korean, which literally...

. Over time, they were extended to provide more advanced text editing features, but its limited original scope led to fundamental limitations. Apple repeatedly stated that TextEdit was not a word processor

Word processor

A word processor is a computer application used for the production of any sort of printable material....

, and therefore providing rich text editing was always left to third-party developers.

Basic limitations of TextEdit include:

• only provides support for 8-bit character sets
• 16-bit internal indexing limits text to a maximum length of about 32,000 characters
• use of QuickDraw
  QuickDraw
  QuickDraw is the 2D graphics library and associated Application Programming Interface which is a core part of the classic Apple Macintosh operating system. It was initially written by Bill Atkinson and Andy Hertzfeld. QuickDraw still exists as part of the libraries of Mac OS X, but has been...
  
   for glyph rendering limited the maximum height of a text block to 32,767 pixels - this could be encountered well before the character limit was hit with larger font sizes.

The first incarnation of TextEdit provided support for only a single style of text, which was applied to all text in the block. This was more than adequate for its intended use, supporting text entry fields. Later, support was added for styled text so that TextEdit could be used for more complex text editing tasks, such as text editing areas in web browsers, etc.

TextEdit remains part of the Carbon APIs on Mac OS X

Mac OS X

Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

, but has been superseded by numerous other solutions including ATSUI in Carbon, the third party WASTE text engine

WASTE text engine

The WASTE is an Apple Macintosh text editing software library. The "text engine" allows Macintosh programmers to easily add advanced text display and editing features to their applications....

 and the NSTextView and related classes within Cocoa.