See my blog post on Marshall Plan and documentation about MarshallingSupport.
It is possible to host an older-versioned component in its own SWF and load it into a newer-versioned app, but there are tradeoffs. On 8/31/12 8:51 AM, "Nhi Le" <nhi...@gmail.com> wrote: Hi, We have an component developed in Flex 3 that we would like to reuse in an application that is using Flex 4. Is it possible to incorporate the two together? If so, please shed some insight. Thanks, nhi -- Alex Harui Flex SDK Team Adobe Systems, Inc. http://blogs.adobe.com/aharui