Word processing involves using computers to prepare documents. Early examples include the typewriter and word processors like Word and WordPerfect that allow formatting while typing. The term "word processing" was coined by IBM in the late 1960s to describe their Magnetic Selectric typewriter and other products. Popular early word processors included the Wang and WordPerfect 5.1 for DOS. Microsoft Word evolved from DOS to Windows versions and introduced new features over time like the ribbon interface in Word 2007 and changes to file extensions from .doc to .docx. Free alternatives like OpenOffice also emerged, and word processing now occurs in the cloud through services like Google Docs and Microsoft Skydrive.