flXHR & flensed
flXHR (and its parent project "flensed") is an open-source project using flash+javascript to create a drop-in replacement of the XMLHTTPRequest object for cross-domain Ajax.
The site and all project data used to live on its own site at http://flensed.com, but has now been moved/dumped here on github to ensure that the project remains open and available for posterity.
Given recent advances such as CORS (Cross-origin Resource Sharing) which implement cross-domain Ajax using the native XHR interface, flXHR has now accomplished its goal and is no longer necessary. It would only be useful in older browsers as a shim.
Moreover, given that flash has become increasingly marginalized in the web development arena, in favor of standards-based and open web technology choices such as HTML5 and JavaScript, this project is no longer being maintained. All content and code are hereby donated to the public domain (sans the MIT license).