EDIT: Daniel reminded me I should update my blog once in an eternity. Please see his comment for RTM info:
This information is a bit dated. With the RTM release, you can now do the following:
Window window = new Window();
window.AllowsTransparency = true;
window.WindowStyle = WindowStyle.None;
This will create a borderless window that allows transparently. Regarding software acceleration, you'll find this interesting:
http://blogs.msdn.com/seema/archive/2006/10/25/layered-windows-sw-is-sometimes-faster-than-hw.aspx
Regards,
- Daniel
Original outdated post:
Just a quick tip. If you've searched online for a way to make a transparent, borderless, or shaped window in WPF (formerly known as Avalon) and you've found the Win32 Interop method of HwndSource and UsesPerPixelOpacity, you might want to just switch to using a Popup with AllowsTransparency set to True. Just remember that currently (February 2006 CTP) this will mean that hardware acceleration won't be used (oh please, please, please add hardware support...)
73a85310-6917-4b85-b691-977bcbf4009a|0|.0|96d5b379-7e1d-4dac-a6ba-1e50db561b04