这些主要是Activities的特性

Add Activity Providers to Internet Explorer 8

Activity providers enhance your ability to work with text that you select on a webpage, enabling you to map addresses, define words, and more. To add an activity provider to Internet Explorer, click the provider's link below. You can set any of these as the default activity provider by selecting the Make this my default activity provider check box in the Add Activity Provider dialog box that appears when you click the link.