Popfly Beta has launched! Anyone can now sign up for our awesome, easy-to-use mashup builder. Just head on over to our website, click the sign in button, and create an account. We've been getting some rave reviews today, and Valleywag is treating it better than their usual sense of disdain, which I think is nigh on unprecedented ;-):

But Microsoft should, nevertheless, be excited about Popfly. Rarely has Redmond produced such a simple, visually appealing tool for developers.