Writing a widget bears some similarities to writing a plugin. In some ways, it's even easier because there is a widget class that you can leverage for some of the functionalities. In other ways, it's also a bit more time-consuming as there's a lot of mandatory code that every widget has to feature.
Widgets
Custom tag cloud widget
In this section, we'll see how to write a widget that displays a custom tag cloud that we can then place in the sidebar. There will also be the possibility to change the title of the widget, and although this is a tag cloud widget, we'll be able to switch tags to categories and display them using a tag-cloud-like style as well. In its final form, the widget will look like...