Review of Popfly with several screen shots
Popfly, currently an invitation-only alpha, is an authoring tool that lets users build simple data mash-ups inside a cute, game-like interface. It's a bit like Pipes, the mash-up creation service Yahoo debuted in February. People were a little confused when Pipes came out, but Popfly is even simpler. Data services appear as floating cubes. You string the cubes together, tell them how to talk to each other and -- voilà -- you've got a mash-up.
Eager to see what Silverlight is all about, I played with PopFly for a couple of hours. While it definitely benefits from its rich user experience and its creators' strong understanding of how non-developers approach common programming problems, I found it not quite as easy to use as I had hoped. I also encountered a few bugs with the Silverlight platform itself that indicate it has some toughening up to do if it's going to seriously challenge Flash.
1. It's alpha software -- don't be surprised if it hangs/crashes occasionally
2. The output/input parameter mapping issue is an inconvenience but isn't rocket science
3. Popfly is likely to become a lot more powerful when it's updated to work with Silverlight 1.1 (i.e., with the .NET Framework and languages)
Overall, I'm very impressed with Popfly so far.
Source: Compiler - Wired Blogs