Microsoft Popfly (internally codenamed Springfield[1]) was a Website that allowed users to create web pages, program snippets, and mashups using the Microsoft Silverlight rich web applications runtime and the set of online tools provided.

Web pages were created without HTML coding, and could be customized by choosing predefined themes, styles, and color schemes.

Completed mashups and Web pages were stored on Popfly Space (100 MB maximum per user), where users also received a customizable profile page and other social networking features.

Users could utilize Visual Studio Express (Visual Studio 2005 Express Editions or higher required) to download the mashups and modify the coding, as well as perform actions such as uploading, sharing, ripping, and rating the mashups.

All sites, references, and resources of popfly were taken down, and this product is considered defunct.