The Sitefinity Widgets Library, WebForms edition, is a set of useful widgets for your pages. The first version includes the YouTube video widget that allows you to to embed YouTube video clips on your pages, while customizing various parameters.
Before adding the new widget to the Toolbox from Administration -> Settings -> Advanced -> , add a new virtual path mapping by going to VirtualPathSettings -> Virtual paths -> Create new and enter:
VirtualPath - ~/SitefinityWidgetsWebForms/*
ResourceLocation – NextWork.SitefinityWidgets.WebForms
ResolverName – EmbeddedResourceResolver