A Windows Presentation Foundation application that runs in the browser with no installation and no security prompt.
From ZDNet:
WPF XBAP runs in the browser, and is clearly meant to compete with the other “web application” solutions including Ajax and Flex 2. It doesn’t seem to be cross platform, although those with Vista can run it without any upgrade, and IE 7 users will have a smooth upgrade process similar to what Adobe is doing with the Flash 8 to 9 upgrade (from what I can tell).
I’m still trying to get information on a possible release date and where this fits into the .NET 3.0 world, but I think this may be a very good option for people developing web applications in a Microsoft environment. If you’re looking for something more lightweight than regular WPF, this could be your option. And if Microsoft can release a plug-in for the Mac that runs WPF XBAP, then all of a sudden we have a ball game. How does the Expression delay play into this? We’ll have to wait and see.
Update: XBAP is just markup for referencing a full blown WPF application. WPF/E is a crowse browser portable subset of WPF funcionality.
From wikipedia:
Windows Presentation Foundation/Everywhere is a cross platform extension to WPF to provide a subset of WPF features, such as hardware accelerated video, vector graphics, and animations to platforms other than Windows Vista. Specifically, WPF/E will be provided as a plug-in for Windows XP, Windows 2000, Mozilla Firefox, Apple Safari and mobile devices.
These extensions will allow the browsers and other applications to use WPF/E graphical capabilities. The browser extensions will be in the line of Macromedia Flash, a highly popular graphic plug-in available for most browsers. Internet Explorer will have native support for WPF in Windows Vista, and will support WPF/E in older versions.
WPF/E will work in concert with XAML and will be scriptable with Javascript, it will also contain a version of the Common Language Runtime so it can execute VB.Net and C# code.
WPF is included with .NET 3.0, WPF/E will be released later.