The license templates on the source files state that the copyright owner is the Apache Software Foundation. For example, root/programs/C#/Frameworks/Infrastructure/CustomControl/Control/WebCustomButton.cs says:

// The ASF licenses this file to you under the Apache License, Version 2.0

Is this true? If not, the license templates should better be updated to declare the copyright owner, using the template included in license/LICENSE.txt.

Sorry for the nit-picking / please forgive me if the ownership of copyright has in fact been transferred to ASF. Thank you and good luck to the people working on the project!