ASDT is an open source plugin which built on top of the Eclipse ( we have introduced it in article A Multi-language Software Development Platform – Eclipse ) platform to develop software targeted to the Flash Platform. It requires Java 5 JRE, Ecilpse 3.2 and MTASC. You can write ActionScript2 code in an integra environment by using of it. You can get latest information of it in following URL:
Eclipse is a kind of universal tool platform comprising an IDE and a plug-in system. It can be used to develop applications in Java and various plug-ins in other language like C, C++, COBOL, Python, PHP. You could write or contribute the flash related plug-in modules like ActionScript Development Tool, Flashout, Flair, IDE for Laszlo…By the way it is free and open source software, you can get more information and download it in following URL:
I think most of people have the following experience: Sometime somebody will delete some useful files by miss in Flex builder. When it happened how disappionted you are and maybe several weeks efforts was disappeared. In fact these deleted files could be restored in Eclipse. Since Flex builder is based on Eclipse, the way could also be used.