CSHTML5 has now become OpenSilver!

We are happy to announce that CSHTML5 has been significantly improved and rebranded to 'OpenSilver', which stands for 'Open-source reimplementation of Silverlight'. It is fully backward compatible and it can be downloaded from Upgrading from CSHTML5 to OpenSilver is very easy.
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New Beta 10 of C#/XAML for HTML5 Available! Here are the Top New Features

September 28, 2016 — The new beta 10.0 of C#/XAML for HTML5 is available! The free Visual Studio extension that enables developers to create HTML5 apps using only C# and XAML has reached a new milestone. With both bug fixes and new features, this update is recommended to all users.

What's new since Beta 9.0:

  • ChildWindow
  • ToolTip
  • ContextMenu
  • MenuItem
  • Popup
  • New "Picker" feature in the XAML Visual Tree Inspector, to select the item to inspect in the Simulator
  • New Visual Studio Item Templates for ChildWindow, ResX, and XAML Resource Dictionary (to use them, right-click on the project in the Solution Explorer, and click "Add" => "New Item...")
  • More DateTime methods: ToShortTimeString, ToLongTimeString, ToShortDateString, ToLocalTime, TimeOfDay
  • RightTapped event (right-click)
  • ScrollBar control
  • Thumb
  • More Linq methods and overloads: Single, SingleOrDefault, LastOrDefault, GroupBy, Min, Max, Sum, Union, ThenBy, Take, Skip, Except, Distinct, ToDictionary, Contains, Intersect, Aggregate
  • ClipToBounds (like in WPF) to crop the content of a control that exceeds its boundaries
  • VisualTreeHelper.FindElementsInHostCoordinates to know what elements are present at a given (X,Y) position (note: it currently only returns the top-most element at that position)
  • FrameworkElement.Parent
  • VisualTreeHelper.GetChildrenCount and GetChild
  • Negative Margins
  • SizeChanged event
  • MinWidth, MinHeight, MaxWidth, and MaxHeight
  • Value coercion in dependency properties
  • StringSplitOptions in String.Split
  • ActualWidth and ActualHeight in Column and Row Definitions
  • Support for non-native ComboBox, that is, a ComboBox that can contain things other than Strings, such as UIElements or DataTemplates. To use such a ComboBox, just set the "UseNativeComboBox" property to false, like this: <ComboBox UseNativeComboBox="False" />
  • New "Advanced Tools" menu in the Simulator with ability to:
    • execute custom JS code
    • view the history of the JS code executed by the Simulator
    • count the number of DOM elements for performance optimization
    • restart the app
    • view the current HTML or save it to file
    • view the html/js compilation log
  • Binding between a string and a value type is now automatic (like in standard XAML)
  • Line, Rectangle, and Ellipse are no longer "sealed" classes
  • Bug fixes:
    • Fixed the "XmlReader is stuck" error during serialization and WCF calls
    • Fixed "cannot construct UInt64 from negative number" exception when dealing with dates
    • Fixed an issue with ScaleTransform.ScaleY and CompositeTransform.ScaleY
    • Fixed all the outstanding issues related to the ListBox control and the HTML-based native ComboBox control
    • Fixed an issue that caused the Path and other shape controls to randomly disappear in the Simulator
    • LinearGradientBrush under FireFox is no longer rotated 90 degrees
    • When removing an item from the visual tree and putting it back, the DataContext is now properly updated
    • Improved the default Height of the TextBox control
    • Support for Thickness using spaces rather than commas in XAML
    • Control.GetTemplatedChild() method no longer throws an exception if the name is not found
    • Dragging an image no longer causes the browser to initiate a drag behavior. This enables the C#/XAML drag-and-drop features (such as the Thumb control or the PointerMoved event) to function properly
    • passing "null" instead of a Metadata in the declaration of a DependencyProperty no longer throws an exception.
    • Fixed an issue related to the alignment and positioning of controls in a Canvas
    • Fixed the exception that was raised when setting PointerEntered without setting PointerExited events
    • Fixed an issue that could prevent ColorAnimation from working when declared outside a ControlTemplate
    • Fixed an issue where (int)(-1) resulted in 2147483647
    • Fixed an issue that prevented using bindings with ElementName inside a ControlTemplate or a DataTemplate
    • Significantly improved the reliability of the DateTime class


Want to migrate a Silverlight application to the web?

=> Read our Silverlight Migration Guide!

Download Now (Free):

  • To download now, go to and click Download.

    (The beta is limited to the first 10,000 downloads. Get it quickly!)

    Users who registered for one of the previous betas have been sent an email containing the download link. If you have not received it, please contact us.

Special offer:

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Get the Professional Edition - before the end of the Beta period - for only $99 instead of $499!

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You may also be interested to read the updated Road Map.

Want to migrate a Silverlight application to the web? Read our Silverlight Migration Guide.

About C#/XAML for HTML5:

C#/XAML for HTML5 is a free extension for Visual Studio that enables developers to create cross-platform HTML5 apps exclusively using C# and XAML.

It is designed for developers using C#, XAML, and Visual Studio to extend application reach to platforms outside the Microsoft ecosystem, including Android, BlackBerry, Chromebook, iOS, Linux, Mac OS, and web browsers. It can be used to migrate Silverlight apps to HTML5, as well as to create new client-side rich web applications without manipulating HTML, CSS, and JavaScript.

Benefits over alternative cross-platform development tools include zero learning curve for C#/XAML developers, a robust well-organized strongly-typed development experience, the ability to share C# code between the client and the server, and the ability to port legacy apps to the modern web with minimal effort, notably to convert Silverlight apps to HTML.

More information and download can be found at:

About Userware:

Userware is a software company founded in 2007 by two experts in Microsoft technologies. It has gained popularity in the recent years for consumer apps such as XLS Editor (#1 Paid Productivity App in the Windows Store for 8 consecutive months), and, a patent-pending online operating system made in Silverlight that can be enhanced Wiki-style by users using an online development environment. With "C#/XAML for HTML5", Userware aims to enable all C#/XAML developers to build cross-platform HTML5 apps with the skills, tools, and code base they already have.

Userware is online at:


You can contact the team behind C#/XAML for HTML5 at:


For more information, please visit