High Quality Content by WIKIPEDIA articles! HTML Components (HTCs) are a nonstandard mechanism to implement components in script as Dynamic HTML (DHTML) "behaviors" in the "Microsoft Internet Explorer" web browser. Such files typically use a .htc extension. HTC is typically an HTML file (with JavaScript/VBScript) and a set elements that define the component. This helps to organize behavior encapsulated script modules that can be attached to parts of a Webpage DOM. In this example, the LI element is given the behavior defined by "hilite.htc" (a file that contains JavaScript code defining highlight/lowlight actions on mouse over). The same hilite.htc can then be given to any element in the HTML page - thus encapsulating the behavior defined by this file.