XML Namesapce in WPF - xmlns

Question

The following XML namespaces references are included in at the top of every new Xaml file.

//http://schemas.microsoft.com/winfx/xaml/presentation
//http://schemas.microsoft.com/winfx/xaml

The winfx/xaml/presentation holds references to a bunch of windows namesapces such as Windows.Navigation, Windows.Controls ect. The winfx/xaml namesapce always(usually by default) has the x alias or prefix. What does the winfx/xaml reference it seems to have a lot of the same elements that can be referenced from winfx/xaml/presentation. I have read the MSDN documentation and can find a list of assemblies associated with winfx/xaml/presentation but I am not sure what the point the winfx/xaml namespace is.

Can anyone explain?

EDIT: Like I said originally, I have read the MSDN docs and I am looking for a more granular answer. Example why can some elements be used interchangeably.

Answer 1

It is a namespace that contains XAML constructs and can be used outside the context of WPF. Details available here.

HTH, Kent

Answer 2

XAML is not just used by WPF thus the seperation of the namespaces! The http://schemas.microsoft.com/winfx/xaml is stuff that is related to XAML and can be reused on other frameworks (Like WF, Silverlight & WCF) where as the http://schemas.microsoft.com/winfx/xaml/presentation contains stuff purely designed for WPF!!!