string that the user types into a line number field and that the editor recognizes as a command operating on that specific line or block of lines, e.g., LC to translate a line to lower case, ))3 to shift a block right three columns. Some editors also support line macros, also known as prefix macros or sequence macros. Despite the name prefix command, some editors allow the sequence field to appear after the text field. Specialised editors Some editors include special features and extra functions, for instance, Source code editors are text editors with additional functionality to facilitate the production of source code. These often feature user-programmable syntax highlighting and code navigation functions as well as coding tools or keyboard macros similar to an HTML editor. Folding editors. This subclass includes so-called "orthodox editors" that are derivatives of Xedit. Editors that implement folding without programing-specific features are usually called outliners (see below). IDEs (integrated development environments) are designed to manage and streamline large programming projects. They are usually only used for programming as they contain many features unnecessary for simple text editing. World Wide Web authors are offered a variety of HTML editors dedicated to the task of creating web pages. These include: Dreamweaver, KompoZer and E Text Editor. Many offer the option of viewing a work in progress on a built-in HTML rendering engine or standard web browser. Most web development is done in a dynamic programming language such as Ruby or PHP using a source code editor or IDE. The HTML delivered by all but the simplest static web sites is stored as individual template files that are assembled by the software controlling the site and do not compose a complete HTML document. Mathematicians, physicists, and computer scientists often produce articles and books using TeX or LaTeX in plain text files. Such documents are often produced by a standard text editor, but some people use specialized TeX editors. Outliners. Also called tree-based editors, because they combine a hierarchical outline tree with a text editor. Folding (see above) can be considered a specialized form of outlining. Collaborative editors allow multiple users to work on the same document simultaneously from remote locations over a network. The changes made by individual users are tracked and merged into the document automatically to eliminate the possibility of conflicting edits. These editors also typically include an online chat component for discussion among editors. Distraction-free