Where to find the source code of a widget?

i would like to find the source code of the widgets, would you know where to find them? I found the class WP_Widget, but i would like to find, for example, the widget with the last articles.

Thanks

The default widgets are defined in wp-includes/default-widgets.php.

To find specific code search the Codex or use queryposts.com. The best tool is your IDE (integrated development environment). All IDEs offer a full text search in a set of files.

Here a screen shot from Eclipse PDT

As you can see it is really flexible – and it’s fast too. See also this question for a basic guide on how to work with WordPress in an IDE.