drag and drop

Modern web applications often have drag and drop interfaces that allow the user to change the layout of a page (like order and place of menu elements), organize personal content (like files and folders) or express selections by movement of control elements. Users are used to such operations from desktop applications, making such web applications easier to understand and use for less tech-savvy users. HTML5 provides built in capabilities for basic drag and drop operations, but usage of of browsers that support HTML5 is still rather low. The usefulness of HTML5 grows every day, but as long as Internet Explorer 6 is still used developers need to look for alternative solutions for many cases. To make an application work on legacy browsers, one must work around the limitations of HTML, which was originally designed for static web documents. While HTML offers rich capabilities to format the contents of a document as you write it, the elements displayed on a HTML page are immutable and don't allow the user to change or move them as he browses the page. The bottom line is that drag and drop can't be implemented by pre-HTML5 HTML alone and requires some external technology to work.