We want to check the unused classes of FLEX SDK to remove them in order to have a light project. To do this, we get the source code of Flex , and we added it in an ActionScript project (on Flash Builder). The problem now is that we want to test an MXML page inside this project but the MXML page is ignored during the execution. The Action Script project only executes the AS file. Do you have some solution for this problem ? Is there another way to do this (testing Flex SDK source code with MXML page) ?