So what is Apollo? Apollo is the code name for what Adobe calls "a cross-operating system runtime... that allows developers to leverage their existing web development skills (Flash, Flex, HTML, JavaScript, Ajax) to build and deploy RIAs to the desktop." Apollo's desktop integration will include installation onto the desktop; application shortcuts, to which all users have already become accustomed; drag and drop capabilities; a clipboard, similar to the clipboards used by Microsoft Word programs; and notifications. Unlike current operating systems, though, Apollo will feature cross-application communication, enabling its many parts to communicate and function as a whole. Apollo's greatest appeal, however, is that it will provide users with a set of APIs (File I/O, Drag and Drop, Full Network API, Local Storage and Settings, etc…) that will automatically synchronize online and offline content. Adobe plans to package Apollo along with Flash and Acrobat for ease of use. And like Flash, Apollo will be a free runtime for users. It will likely be downloaded along with Flash when users click the automated-prompt built into the site by the developer.

Apollo enables familiar application interaction models, including drag-and-drop support, rich clipboard access, and desktop and system shortcuts. Furthermore, Apollo applications run as regular applications, and do not have to run within another application or shell (as web applications do by running within the browser).

This alpha version of the Apollo runtime provides developers with the opportunity to begin building applications for Apollo. Future releases will provide more stability, more desktop integration, and enhanced support for Ajax developers

Source: http://www.codeapollo.com