Simple drop-in replacement of the standard control. Get a superior listbox without wasting any time, thanks to an API design that lets you integrate it into any project using the stock Silverlight listbox. (See the feature list.)  

Intelligent, virtualized background data retrieval. Deliver apps that won’t make end-users wait. The remote data engine only gets records as needed, reducing the amount transferred. Optimized network communications and queries make things snappier. And an entirely asynchronous architecture keeps the app responsive, always.

Powerful grouping, navigation, and filtering. Help your end-users get a better handle on the data thanks to grouping with sticky headers. A navigation control takes users directly to the group they’re looking for. And a search box filters data quickly and easily.

Smooth scrolling and fluid animations. Provide a superior user experience! More than just eye candy, these effects reduce the perception of lag, thanks to the time required to execute them. And because items fade in/out and glide fluidly, visual tracking of items is improved.

Multiple views and themes. Easily create unique apps that provide animated switching between multiple views. In addition to the traditional vertical list layout, a horizontal list layout and “path” views are provided. Six beautiful themes will match the style of your application.

More than a license: it's a subscription! In addition to a perpetual license for versions received during the subscription, you get a year of these great services: expert priority support and access to new versions, new features, and bug fixes. Choosing the Blueprint subscription adds the full C# and XAML source.