Adobe® AIR™, formerly code-named Apollo, is a cross-operating system runtime that allows developers to use their existing web development skills to build and deploy rich Internet applications to the desktop.
For web developers this will allow to use tools such as AJAX and Flex to build Rich Internet Applications that run on the desktop! Yes on the desktop. You can even build applications that will work in an online and offline mode.
Some good articles, info and examples of Apollo Flex apps can be found at the following places ...