1. A computer-implemented system comprising: a widgetizer trigger to receive at a server computer system, from a web browser application running at a client computer system, a request to widgetize a web-based computer application to permit the computer application to be run as a desktop widget at the client computer system; and a definition module to provide to the client computer application, in response to the request to widgetize, a definition file associated with the computer application, the definition file comprising a reference link to the computer application, the reference link including one or more parameters, the one or more parameters to instruct the computer application to generate output in a format suitable for use by a widget engine provided at the client computer system.