We just annouced Popfly,  a fun & easy way to build and share mashups, gadgets, Web pages, and applications. Popfly consists of two parts:

1. Popfly Creator is a set of online visual tools for building Web pages and mashups without coding.

2. Popfly Space is an online community of creators where you can host, share, rate, comment and even remix creations from other Popfly users.

http://blogs.msdn.com/somasegar/

And a cool tidbit: Popfly also uses Silverlight

So what is Silverlight ? If you have not yet heard about Silverlight (used to be called WPF/E ), its a browser plug-in runtime environment or cross-browser cross-platform (Macs supported) CLR supporting Ajax, VB, C#, Python, and Ruby .

It alllows the creation of rich interactive multi-media browser apps. Development environment will be Orcas , the upcoming Visual Studio release or the Expression tools family.

Where WPF is for smart client apps and requires the .NET framework , Silverlight only requires a light weight browser plug-in and is easy to deploy.

http://blogs.zdnet.com/Stewart/?p=356

Philippe