Gmail developers decided that you need to give the opportunity to enjoy a variety of web interface. Soon each of us will receive in its location a whole set of various gadgets. Each of them can be connected with one click of the mouse (more precisely, by entering the URL of the form www.google.com/ig/modules/youtube_videos.xml ), and it will immediately go to the left panel in the mail interface. They started with Google Calendar gadgets and Google Docs.
According to the developers, this functionality is most in demand by Gmail users, who want to see the schedule of their Google Calendar, right from their inbox, and also use the Google Docs search window.
Programmers claim that they are obsessed with the performance of gadgets, so that in the future they will in no way slow down the system, as they are now. ')
Official Gmail Blog