Internet extension?

With the advent of the GUI, the issue of file management and interface behavior arose. The Windows platform allowed multiple applications to be associated with a given file type, and different file "actions" defined for opening, editing, viewing, and so-forth by means of a context menu. File managers such as Windows Explorer can have applications assigned for almost every file name extension. For example, a text editor for .txt, a word processor for .doc or .odt, a web browser for .htm or .html, PDF viewer or editor for .pdf, a graphics program for .png, .gif or .jpg, a spreadsheet program for .xls or .ods, etc.