The installer lets you install a W3C Widget as a new application, which on the Mac means you turn it into a new native application that lives in your Applications folder, has a Dock icon, and launches in the usual way.
Widgets can either float on top of your other windows or act like any other application and be covered by other windows as they come into focus.
You don’t actually need to have Opera open to use widgets – though it does have a Widget Manager sidebar with access to Opera’s site for finding new ones. However you can also install widgets just by double-clicking .wgt files. (If you install the same .wgt file multiple times you end up with multiple versions of the application, rather than updating the same one, which is mildly irritating.)
To try it out I used some of the widgets we created for Apache Wookie (incubating). One of the first things I noticed is that Opera uses a transparent background. This is really nice as you can have odd-shaped widgets, but if you haven’t set a background for your widget they do look odd.
Here’s the “weather” example widget from Wookie running on my Mac:
The application’s menus enable you to set the zoom, position (e.g. always on top) and permissions of the widget (e.g. for geolocation). (This also has a “show notifications” setting, however I couldn’t get this working – I think it must require using the older Opera Widgets spec rather than W3C Widgets, which doesn’t have a “showNotification()” method. I guess eventually W3C Web Notifications may work here. Or not.)
The icon in the widget package is used in the Dock and as the application icon:
Its really nice seeing the same widgets working across the desktop, on mobile and in websites – while thats the whole point of the W3C Widgets spec, its quite another thing to see it realised in shipping products.