PDC 2005: Microsoft lays out its plan for Avalon

Avalon aka Windows Presentation Foundation is one of the major focuses of Microsoft here.  In fact, Avalon is getting more emphasis at PDC than any other new technology in IMO.

Its Goal: Replace GDI (which is nearly 20 years old) with a new graphics system that takes advantage of the latest advances in graphics hardware.  But replacing GDI is a bit of an understatement.  It replaces GDI in the same way that spreadsheets replace counting on ones fingers.

It lets people create applications on the desktop that have the same kinds of graphical performance as a PC game.

What do developers have today? GDI, GDI+, DirectShow.  We've done quite a bit with these things (ObjectDock, DesktopX, WindowBlinds, etc.).  But they are still limited.

Future development should make use of Direct3D, Windows Media Foundation, Windows Presentation Foundation (Avalon).

So how about Direct3D vs. Avalon?  Direct3D provides much finer control but also requires more work.  Avalon, by contrast, is designed to allow people to do visually exciting things with less effort but isn't nearly as low level. Incidentally, Direct3D 10 will only be available to Windows Vista users.

What's nice about Windows Vista's new display driver model is that the GPU is virtualized so multiple applications can share the processor cleanly (something that you can't do on Windows XP currently). 

Windows Media Foundation is a new set of APIs to handle audio and video playback  They are being set up to replace DirectShow and Windows Media SDK.  One of the benefits is WMF is that it provides better resilience for audio and video.

Menawhile, Avalon (Windows Presentation Foundation) is designed to encourage the use of resolution independent application development through the use of vector-based content.