A markup language is a system for annotating a document in a way that is syntactically distinguishable from the text.The idea and terminology evolved from the  marking up  of paper manuscripts, i.e., the revision instructions by editors, traditionally written with a blue pencil on authors' manuscripts.ML (Extensible Markup Language) is a meta markup language that is now widely used. XML was developed by the World Wide Web Consortium, in a committee created and chaired by Jon Bosak. The main purpose of XML was to simplify SGML by focusing on a particular problem — documents on the Internet.