http://archive.eclipse.org/eclipse/downloads/drops/R-3.5.1-200909170800/index.php
-> JDT Runtime Binary : Download the appropriate file for your OS
-> Extract zip file
-> Then copy the files in features/* into your “Adobe Flash Builder 4/features” folder.
-> Do the same for plugins/* -> “Adobe Flash Builder 4/plugins”.
-> Restart Flash Builder 4 and now you should have the Ant UI available.
[Link] http://renaun.com/blog/2010/03/ant-and-release-flash-builder-4-standalone-eclipse-351/
