Editing TextEdit (section)

== Implementation ==
TextEdit replaced the text editor of [[classic Mac OS|previous Macintosh operating systems]], [[SimpleText]]. TextEdit uses the [[Cocoa text system]] to read and write documents in [[Rich Text Format]] (RTF), [[Rich Text Format Directory]], [[plain text]], and [[HTML]] formats, and can open (but not save) old SimpleText files. It also has access to the operating system's built-in [[spell checker|spell-checking]] service. The version included in [[Mac OS X Panther|Mac OS X v10.3]] added the ability to read and write documents in Word format, and the version in [[Mac OS X Tiger|Mac OS X v10.4]] added the ability to read and write [[Microsoft Office XML formats|Word XML documents]]. The version included in [[Mac OS X Leopard|Mac OS X v10.5]] added read and write support for [[Office Open XML]] and [[OpenDocument|OpenDocument Text]]. The version included in [[Mac OS X Snow Leopard|Mac OS X v10.6]] added automatic spelling correction, support for data detectors, and text transformations. The version included in [[Mac OS X Lion|Mac OS X v10.7]] added versioning of files, and Autosave similar to iOS.

Formatted text, justification, and even the inclusion of graphics and other multimedia elements are supported by TextEdit, as well as the ability to read and write to different [[character encoding]]s, including [[Unicode]] ([[UTF-8]] and [[UTF-16]]). TextEdit automatically adjusts letter spacing in addition to word spacing while justifying text. TextEdit does not support multiple columns of text.

The high-resolution TextEdit 1.5 icon found in Mac OS X versions starting with 10.5 (Leopard) features an extract from Apple's "[[Think different]]" ad campaign. This was replaced by a blank sheet of notebook paper in 10.10 (Yosemite).