In case you were wondering how to get involved with the Flex SDK development, grab a “Subversion”:http://subversion.tigris.org/ client and checkout this repo: “http://opensource.adobe.com/svn/opensource/flex/sdk/”:http://opensource.adobe.com/svn/opensource/flex/sdk/ or just click on that link to look through the repo in the browser.
If you just want to view change logs for the most recent available downloads, “go here”:http://opensource.adobe.com/wiki/display/flexsdk/Download+Flex+3.