Microsoft’s new free ecosystem in alpha is named Popfly.  The alpha service currently has a waiting list.

It provides for the creation and hosting of mashup content in a community (Popfly Space) using building ‘blocks’ in a non-developer-orientated UI.  Finished projects can be hosted (by the provided embed code or directly to sites that support the MetaWoblog API) on other communities (that support iframe) or as Vista Sidebar gadgets. 

So for example, at the basic level you can create and publish your own slide show or psuedo 3D photo sphere or Virtual Earth view (with photos geographically positioned) that pulls pictures from a Live Spaces or Flickr account.

Presentation can be done with Silverlight 1.0, AJAX, or DHTML (see my posts on this for more information on Silverlight).  It is a web-browser client-side technology (not for creating say ASP.NET server-side applications).

The Popfly Creator is an online tool for creating the single-page mashup applications, including the ASP.NET AJAX client library.  It graphically shows the blocks and how they are connected up.  There are javascript editing options (including intellisense!) for advanced users.

Users can create and share their own blocks, and there appears to be a possible monetization opportunity there too (see the FAQ).

There is also rudimentary cross-user anonymous application data persistance (e.g. for voting results).

The service is aimed primarily at non-professional developers to build things without code, but there’s also a plug-in for Visual Studio (all versions) called Popfly Explorer.

See the Popfly website and video for more information.

[Via: Robert Scoble]