One of the primary ways that Sitefinity is extended is through custom widgets. These custom widgets enable you to tackle challenges that might not be addressed with Sitefinity’s out-of-the-box features. A user-friendly interface (known as a ControlDesigner) can then be added to these widgets to enable content authors to easily interact with these custom tools.
These 2 topics (custom widgets & ControlDesigners) are vital for any developer working with Sitefinity. The video below serves as a basic introduction to these important topics.
The code shown in this video is found here.
If you’re looking for real-world widget & ControlDesigner examples, then check out our SDK or our official documentation.