Hi, We have a .fla file. We would like an IDE to open .fla file and debug the action script. We tried Flash Develop (open source), but this IDE does not open .fla files. Is there any other free/open source IDE we could use for opening and debugging .fla files?
FLA is generally not supported by applications other than Flash. The reason for this is that FLA is a binary format that closely resembles how state data is stored internally by the Flash IDE, which means that save and load operations are very fast for the IDE, but has the downside that it's excessively difficult for anyone else to support. (This is changing from next version, when they're switching to an XML-based text file format.)
If there's a short-term need, your best bet is to use the Flash IDE, and finish what you need to do before the free trial ends (30 or 60 days, I forget). You could also investigate using JSFL (javascripts with access to the Flash IDE's DOM) to get data out of the FLAs and into common formats, if you like. I don't know of any other approaches though, except to wait for CS5 and then wait for other programs to learn the new flash file format.